A156992 → D+1
nonnegative coefficientsonly rational roots
Proved for all n all roots real, in (−∞, 0]coefficients of one signHadamard kernelinterlacing (weak)
Recurrence
\(\left(x + n\right)\,P_{n}(x) = \left(1 + 2\,x + x^{2} + 2\,n + 3\,n x + n x^{2} + n^{2} + n^{2} x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)
Rows ?
| n | x0 | x1 | x2 | x3 | x4 | x5 | x6 | x7 | Pn(1) |
|---|---|---|---|---|---|---|---|---|---|
| 0 | 1 | 1 | |||||||
| 1 | 4 | 2 | 6 | ||||||
| 2 | 18 | 24 | 6 | 48 | |||||
| 3 | 96 | 216 | 144 | 24 | 480 | ||||
| 4 | 600 | 1920 | 2160 | 960 | 120 | 5760 | |||
| 5 | 4320 | 18000 | 28800 | 21600 | 7200 | 720 | 80640 | ||
| 6 | 35280 | 181440 | 378000 | 403200 | 226800 | 60480 | 5040 | 1290240 | |
| 7 | 322560 | 1975680 | 5080320 | 7056000 | 5644800 | 2540160 | 564480 | 40320 | 23224320 |
Compute more
?
Technical details
- Node id
n-10f9788d2ae8ab73· revision 0 · JSON- Definition source
derived:one_plus_derivative- Fingerprint
f6-e99c3824c4864868
Observed on the stored rows ?
- Degrees: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 (affine: slope 1, intercept 0)
- Palindromic rows: no
- γ-positive (gamma_positive): no
- Nonnegative coefficients (
nonn): yes - Only rational roots (
rr_by_factors: every nonzero row is a product of linear factors over ℚ): yes
Matches ?
No OEIS matches.
Submission text ?
Atlas rows n = 0, …, ascending powers of x
%e ExampleTriangle begins: 0: 1; 1: 4, 2; 2: 18, 24, 6; 3: 96, 216, 144, 24; 4: 600, 1920, 2160, 960, 120; 5: 4320, 18000, 28800, 21600, 7200, 720; 6: 35280, 181440, 378000, 403200, 226800, 60480, 5040; 7: 322560, 1975680, 5080320, 7056000, 5644800, 2540160, 564480, 40320; 8: 3265920, 23224320, 71124480, 121927680, 127008000, 81285120, 30481920, 5806080, 362880; 9: 36288000, 293932800, 1045094400, 2133734400, 2743372800, 2286144000, 1219276800, 391910400, 65318400, 3628800;
%F FormulaThe row polynomials satisfy (n+x)*P(n,x) = (n^2+2*n+1+(n^2+3*n+2)*x+(n+1)*x^2)*P(n-1,x) for n >= 1, with P(0,x) = 1.
%t MathematicaP[0, x_] := 1;
P[n_, x_] := P[n, x] = Expand[Together[((n^2 + 2*n + 1 + (n^2 + 3*n + 2)*x + (n + 1)*x^2)*P[n - 1, x])/(n + x)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten%o PARI/GPP(N) = {my(v = vector(N + 1)); v[1] = 1; for(n = 1, N, my(i = n + 1); v[i] = ((n^2 + 2*n + 1 + (n^2 + 3*n + 2)*x + (n + 1)*x^2)*v[i - 1])/(n + x)); v};
row(n, p) = {my(c = Vecrev(p)); c};
T(N) = {my(v = P(N)); concat(vector(#v, i, row(i - 1, v[i])))};
T(9)polytool c48629374597
Properties
- Real-rooted? Every row P_n, n ≥ 0, is zero or real-rooted with all roots in (−∞, 0]
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Coefficients of one sign?
Every nonzero row, n ≥ 0: the coefficients of P_n have one sign
derived from Laguerre’s theorem on differential operators
-
Hadamard kernel (Malo)?
Rows P_n, n ≥ 0, are Hadamard kernels (preserve real-rootedness)
derived from Laguerre’s theorem on differential operators
- Interlacing of consecutive rows? Rows P_(m-1), P_m interlace (weak, unordered) for every m ≥ 1
Proof chains ? JSON
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Laguerre’s theorem on differential operators [SP14] polytool ? step ›
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from
Triangle T(n,k) = n!*binomial(n-1, k-1) for 1 <= k <= n, read by rows.?
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Row-hypergeometric rows (multiplier sequences) [SP14; Bra15, Thm 7.1 of arXiv:1410.6601] polytool RealRooted RealRooted.isPFMultiplierSequence_eval_of_roots_nonpos RealRooted RealRooted.isPFMultiplierSequence_inv_ascPochhammer RealRooted RealRooted.IsPFMultiplierSequence.mul ? step › direct check
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Affine, reversal and Möbius substitutions (elementary) polytool ? step ›
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from
Triangle T(n,k) = n!*binomial(n-1, k-1) for 1 <= k <= n, read by rows.?
- ↑ Row-hypergeometric rows (multiplier sequences) (above)
- ↑ Liu–Wang theorem (above)
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Geometric basis map (elementary) polytool ? step ›
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from
theta_plus_one of Triangle read by rows: row n consists of n zeros followed by n!.?
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Laguerre’s theorem on multiplier sequences [SP14; Bra15, Thm 7.1 of arXiv:1410.6601] polytool ? step ›
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from
Triangle read by rows: row n consists of n zeros followed by n!.?
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Affine, reversal and Möbius substitutions (elementary) polytool ? step ›
- ↑ Affine, reversal and Möbius substitutions (elementary) (above)
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from
Triangle read by rows: row n consists of n zeros followed by n!.?
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Laguerre’s theorem on multiplier sequences [SP14; Bra15, Thm 7.1 of arXiv:1410.6601] polytool ? step ›
-
-
from
theta_plus_one of Triangle read by rows: row n consists of n zeros followed by n!.?
-
from
Triangle T(n,k) = n!*binomial(n-1, k-1) for 1 <= k <= n, read by rows.?
- ↑ Geometric basis map (elementary) (above)
- ↑ Iterated real-rootedness preservers (above)
- ↑ Parent-row provers of polytool (above)
- ↑ Affine, reversal and Möbius substitutions (elementary) (above)
-
-
from
Triangle T(n,k) = n!*binomial(n-1, k-1) for 1 <= k <= n, read by rows.?
Related ?
Same fingerprint ?
- A178822 → D+1
- A178822 → basis A013609 → D+1
- A093375 → D → D
- A028326 → D → θ+1
- A038208 → D → θ+1
- A085880 → basis A013609 → D+1
- A085880 → D+1
- A007318 → ×(−(1/2)n+(1/2)n²) → D+1
- A356546 → θ+1
- A124860 → θ+1
- basis-map coefficients of A113214, shifted → D → θ+1
- A135065 → D+1
- A028326 → basis A013609 → θ+1
- A027465 → basis A013611 → D+1
- A094305 → θ+1
- A028326 → D+1
- A131431 → D+1 → basis A007318
- A038221 → θ+1
- A135838 → θ+1
- A178822 → θ+1
- A028326 → θ+1
- A196347 → θ+1
- A038325 → basis A013609 → D+1
- A178821 → D+1
- A085880 → basis A013609 → θ+1
- A085881 → basis A013609 → θ+1
- A356546 → D+1
- A007318 → ×(−(1/2)n+(1/2)n²) → θ+1
- A038325 → θ+1
- A038208 → θ+1
- A156992 → basis A013609 → D+1
- basis-map coefficients of A026729 → basis A007318 → D+1
- A038325 → basis A013609 → θ+1
- A038325 → D+1
- A038208 → D → D+1
- A134346 → D+1
- A156992 → basis A013609 → θ+1
- A093375 → D
- A028326 → D → D+1
- basis-map coefficients of A127647 → θ+1
- basis-map coefficients of A127647 → D+1
- A038221 → basis A013609 → D+1
- A135838 → D+1
- A085881 → θ+1
- A178821 → basis A013609 → D+1
- basis-map coefficients of A026729 → basis A007318 → θ+1
- A120910 → basis A013610 → θ+1
- basis-map coefficients of A113214, shifted → basis A013609 → θ+1
- A038221 → basis A013609 → θ+1
- A376827 → θ+1
- A038221 → D+1
- A085881 → basis A013609 → D+1
- A156992 → θ+1
- A103406: Triangle read by rows: n-th row = unsigned coefficients of the characteristic polynomials of an n X n matrix w…
- A178821 → θ+1
- basis-map coefficients of A112227 → x ↦ x+1 → D+1
- A216973 → θ+1
- A094305 → D+1
- A124860 → D+1
- A093375: Array T(m,n) read by ascending antidiagonals: T(m,n) = m*binomial(n+m-2, n-1) for m, n >= 1.
- basis-map coefficients of A026729, shifted → basis A007318 → θ+1
- A038330 → basis A013611 → θ+1
- A038330 → basis A013611 → D+1
- A196347 → D+1
- basis-map coefficients of A113214, shifted → θ+1
- A344565 → D+1
- A134346 → θ+1
- A178822 → basis A013609 → θ+1
- basis-map coefficients of A113214, shifted → D+1
- A356546 → basis A013609 → θ+1
- A376827 → D+1
- A135065 → θ+1
- basis-map coefficients of A026729, shifted → basis A007318 → D+1
- A131431 → x ↦ x+1 → D+1
- A038208 → D+1
- A178820 → basis A013609 → θ+1
- A178820 → D+1
- A038338 → basis A013609 → D+1
- A003506 → D → θ+1
- A344565 → θ+1
- basis-map coefficients of A113214, shifted → basis A013609 → D+1
- A028326 → basis A013609 → D+1
- A027465 → basis A013611 → θ+1
- A038338 → basis A013609 → θ+1
- A085880 → θ+1
- A356546 → basis A013609 → D+1
- A196347 → basis A013609 → θ+1
- A196347 → basis A013609 → D+1
- A085881 → D+1
- A038338 → D+1
- A085880 → D → D+1
- A120910 → basis A013610 → D+1
- A178820 → θ+1
- A178820 → basis A013609 → D+1
- basis-map coefficients of A113214, shifted → D → D+1
- A178821 → basis A013609 → θ+1
- A131431 → x ↦ x+1 → θ+1
- basis-map coefficients of A112227 → x ↦ x+1 → θ+1
- A085880 → D → θ+1
- A038338 → θ+1
References
- [Bra06] Petter Brändén. On linear transformations preserving the Pólya frequency property. Transactions of the American Mathematical Society, 358(8):3697–3716, February 2006. doi:10.1090/s0002-9947-06-03856-6
- [Bra15] Petter Brändén. Unimodality, log-concavity, real-rootedness and beyond. Handbook of enumerative combinatorics, :437–483, March 2015. doi:10.1201/b18255-10
- [LW07] Lily L. Liu and Yi Wang. A unified approach to polynomial sequences with only real zeros. Advances in Applied Mathematics, 38(4):542–560, May 2007. doi:10.1016/j.aam.2006.02.003
- [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.