basis-map coefficients of A021012 → θ+1 → D+1
only rational roots
Proved for all n all roots real, in (−∞, 0]coefficients of one signHadamard kernel
Recurrence
\(\left(-2 + x + n\right)\,P_{n}(x) = \left(n x - n x^{2} - n^{2} x\right)\,P_{n-1}(x)\)
\(P_{1}(x) = 1\)
Rows ?
| n | x0 | x1 | x2 | x3 | x4 | x5 | x6 | x7 | x8 | x9 | x10 | x11 | x12 | x13 | x14 | Pn(1) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 1 | 1 | ||||||||||||||
| 2 | -2 | -2 | -4 | |||||||||||||
| 3 | 0 | 12 | 6 | 18 | ||||||||||||
| 4 | 0 | 0 | -72 | -24 | -96 | |||||||||||
| 5 | 0 | 0 | 0 | 480 | 120 | 600 | ||||||||||
| 6 | 0 | 0 | 0 | 0 | -3600 | -720 | -4320 | |||||||||
| 7 | 0 | 0 | 0 | 0 | 0 | 30240 | 5040 | 35280 | ||||||||
| 8 | 0 | 0 | 0 | 0 | 0 | 0 | -282240 | -40320 | -322560 | |||||||
| 9 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2903040 | 362880 | 3265920 | ||||||
| 10 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | -32659200 | -3628800 | -36288000 | |||||
| 11 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 399168000 | 39916800 | 439084800 | ||||
| 12 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | -5269017600 | -479001600 | -5748019200 | |||
| 13 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 74724249600 | 6227020800 | 80951270400 | ||
| 14 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | -1133317785600 | -87178291200 | -1220496076800 | |
| 15 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 18307441152000 | 1307674368000 | 19615115520000 |
Compute more
?
Technical details
- Node id
n-c5b5d802fc81fcee· revision 0 · JSON- Definition source
derived:one_plus_derivative- Fingerprint
f6-2327141074f67bdf
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 -1)
- Palindromic rows: no
- γ-positive (gamma_positive): no
- Nonnegative coefficients (
nonn): no - 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 = 1, …, ascending powers of x
%e ExampleTriangle begins: 1: 1; 2: -2, -2; 3: 0, 12, 6; 4: 0, 0, -72, -24; 5: 0, 0, 0, 480, 120; 6: 0, 0, 0, 0, -3600, -720; 7: 0, 0, 0, 0, 0, 30240, 5040; 8: 0, 0, 0, 0, 0, 0, -282240, -40320; 9: 0, 0, 0, 0, 0, 0, 0, 2903040, 362880; 10: 0, 0, 0, 0, 0, 0, 0, 0, -32659200, -3628800;
%F FormulaThe row polynomials satisfy (n-2+x)*P(n,x) = -((n^2-n)*x+n*x^2)*P(n-1,x) for n >= 2, with P(1,x) = 1.
%t MathematicaP[1, x_] := 1;
P[n_, x_] := P[n, x] = Expand[Together[(-((n^2 - n)*x + n*x^2)*P[n - 1, x])/(n - 2 + x)]];
Table[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten%o PARI/GPP(N) = {my(v = vector(N)); v[1] = 1; for(n = 2, N, my(i = n); v[i] = (-((n^2 - n)*x + n*x^2)*v[i - 1])/(n - 2 + x)); v};
row(n, p) = {my(c = Vecrev(p)); c};
T(N) = {my(v = P(N)); concat(vector(#v, i, row(i, v[i])))};
T(10)polytool c48629374597
Properties
- Real-rooted? Every row P_n, n ≥ 1, is zero or real-rooted with all roots in (−∞, 0]
-
Coefficients of one sign?
Every nonzero row, n ≥ 1: the coefficients of P_n have one sign
derived from Laguerre’s theorem on differential operators
-
Hadamard kernel (Malo)?
Rows P_n, n ≥ 1, are Hadamard kernels (preserve real-rootedness)
derived from Laguerre’s theorem on differential operators
Proof chains ? JSON
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Laguerre’s theorem on differential operators [SP14] polytool ? step ›
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from
theta_plus_one of basis-map coefficients of Triangle of coefficients in expansion of x^n in terms of Laguerre polynomia…?
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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
basis-map coefficients of Triangle of coefficients in expansion of x^n in terms of Laguerre polynomials L_n(x).?
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Affine, reversal and Möbius substitutions (elementary) polytool ? step ›
- ↑ Affine, reversal and Möbius substitutions (elementary) (above)
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from
basis-map coefficients of Triangle of coefficients in expansion of x^n in terms of Laguerre polynomials L_n(x).?
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-
from
theta_plus_one of basis-map coefficients of Triangle of coefficients in expansion of x^n in terms of Laguerre polynomia…?
Related ?
Same fingerprint ?
- A127773 → D+1
- basis-map coefficients of A026729, shifted → D+1
- image under θ+1 → (θ+1)² → D+1
- A136572 → D → D+1
- basis-map coefficients of A026729 → (θ+1)² → D+1
- basis-map coefficients of A030528, shifted → (θ+1)² → D+1
- basis-map coefficients of A026729, shifted → D → D+1
- image under θ+1 → θ+1 → D+1 → reverse
- basis-map coefficients of A026729, shifted → θ+1 → D+1
- A127648 → D → D+1
- A136572 → θ+1 → D+1
- basis-map coefficients of A021012 → D+1
- A130123 → D → D+1
- A127648 → (θ+1)² → D+1
- A131431 → D+1 → reverse
- A136572 → D+1
- basis-map coefficients of A030528, shifted → D+1
- A132440 → θ+1 → D+1
- basis-map coefficients of A030528, shifted → D → D+1
- A136572 → (θ+1)² → D+1
- A130123 → θ+1 → D+1
- A131436 → D+1
- A023531 → D+1
- Hadamard-factor parent of A127773 → D+1
- image under θ+1 → D+1
- basis-map coefficients of A026729 → D+1
- A127773 → D → D+1
- A131431 → D+1 → D
- A131431 → D+1
- basis-map coefficients of A026729 → D → D+1
- A127773 → θ+1 → D+1
- A131431 → (θ+1)² → D+1
- image under θ+1 → θ+1 → D+1
- A130123 → (θ+1)² → D+1
- A132440 → D+1
- basis-map coefficients of A026729, shifted → (θ+1)² → D+1
- A131431 → θ+1 → D+1
- image under θ+1 → θ+1 → D+1 → D
- basis-map coefficients of A030528, shifted → θ+1 → D+1
- A130123 → D+1
References
- [Bra15] Petter Brändén. Unimodality, log-concavity, real-rootedness and beyond. Handbook of enumerative combinatorics, :437–483, March 2015. doi:10.1201/b18255-10
- [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.