basis-map coefficients of A026729, shifted → basis A007318 → (θ+1)²
Proved for all n all roots real, in (−∞, 0]coefficients of one signHadamard kernel
Recurrence
\(\left(1 - 4\,x + x^{2} + 3\,n x - 2\,n x^{2} + n^{2} x^{2}\right)\,P_{n}(x) = \left(-1 + x^{2} - 3\,n x - 3\,n x^{2} - n^{2} x^{2} - n^{2} x^{3}\right)\,P_{n-1}(x)\)
\(P_{1}(x) = 1\)
Rows ?
| n | x0 | x1 | x2 | x3 | x4 | x5 | x6 | x7 | Pn(1) |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 1 | 1 | |||||||
| 2 | -1 | -4 | -5 | ||||||
| 3 | 1 | 8 | 9 | 18 | |||||
| 4 | -1 | -12 | -27 | -16 | -56 | ||||
| 5 | 1 | 16 | 54 | 64 | 25 | 160 | |||
| 6 | -1 | -20 | -90 | -160 | -125 | -36 | -432 | ||
| 7 | 1 | 24 | 135 | 320 | 375 | 216 | 49 | 1120 | |
| 8 | -1 | -28 | -189 | -560 | -875 | -756 | -343 | -64 | -2816 |
Compute more
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Technical details
- Node id
n-02083e8fdf8aee31· revision 0 · JSON- Definition source
derived:theta_plus_one_squared- Fingerprint
f6-d42e6339eab21b9c
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): no
Matches ?
No OEIS matches.
Submission text ?
Atlas rows n = 1, …, ascending powers of x
%e ExampleTriangle begins: 1: 1; 2: -1, -4; 3: 1, 8, 9; 4: -1, -12, -27, -16; 5: 1, 16, 54, 64, 25; 6: -1, -20, -90, -160, -125, -36; 7: 1, 24, 135, 320, 375, 216, 49; 8: -1, -28, -189, -560, -875, -756, -343, -64; 9: 1, 32, 252, 896, 1750, 2016, 1372, 512, 81; 10: -1, -36, -324, -1344, -3150, -4536, -4116, -2304, -729, -100;
%F FormulaThe row polynomials satisfy (1+(3*n-4)*x+(n^2-2*n+1)*x^2)*P(n,x) = -(1+3*n*x+(n^2+3*n-1)*x^2+n^2*x^3)*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[(-(1 + 3*n*x + (n^2 + 3*n - 1)*x^2 + n^2*x^3)*P[n - 1, x])/(1 + (3*n - 4)*x + (n^2 - 2*n + 1)*x^2)]];
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] = (-(1 + 3*n*x + (n^2 + 3*n - 1)*x^2 + n^2*x^3)*v[i - 1])/(1 + (3*n - 4)*x + (n^2 - 2*n + 1)*x^2)); 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]
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Coefficients of one sign?
Every nonzero row, n ≥ 1: the coefficients of P_n have one sign
derived from Laguerre’s theorem on multiplier sequences
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Hadamard kernel (Malo)?
Rows P_n, n ≥ 1, are Hadamard kernels (preserve real-rootedness)
derived from Laguerre’s theorem on multiplier sequences
Proof chains ? JSON
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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
shift_x_plus_one of basis-map coefficients of Square array of binomial coefficients T(n,k) = binomial(n,k), n >= 0, k >…?
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Affine, reversal and Möbius substitutions (elementary) polytool ? step ›
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from
shift_x_plus_one of basis-map coefficients of Square array of binomial coefficients T(n,k) = binomial(n,k), n >= 0, k >…?
Related ?
Same fingerprint ?
- basis-map coefficients of A113214, shifted → D → (θ+1)²
- basis-map coefficients of A127647 → (θ+1)²
- A028326 → basis A013609 → (θ+1)²
- A178820 → (θ+1)²
- A125092: Triangle read by rows: T(n,k) = (k+1)^2*binomial(n,k) (0 <= k <= n).
- A135065 → (θ+1)²
- A376827 → (θ+1)²
- A038221 → (θ+1)²
- A178821 → basis A013609 → (θ+1)²
- A125092 → reverse
- A085881 → (θ+1)²
- A027465 → basis A013611 → (θ+1)²
- basis-map coefficients of A112227 → x ↦ x+1 → (θ+1)²
- A135838 → (θ+1)²
- A120910 → basis A013610 → (θ+1)²
- A028326 → (θ+1)²
- A038208 → D → (θ+1)²
- A124860 → (θ+1)²
- A196347 → (θ+1)²
- A038338 → basis A013609 → (θ+1)²
- basis-map coefficients of A026729 → basis A007318 → (θ+1)²
- A178820 → basis A013609 → (θ+1)²
- A038325 → (θ+1)²
- basis-map coefficients of A113214, shifted → basis A013609 → (θ+1)²
- A131431 → x ↦ x+1 → (θ+1)²
- basis-map coefficients of A113214, shifted → (θ+1)²
- A003506 → D → (θ+1)²
- A038330 → basis A013611 → (θ+1)²
- A028326 → D → (θ+1)²
- A085880 → D → (θ+1)²
- A038338 → (θ+1)²
- A038325 → basis A013609 → (θ+1)²
- A356546 → (θ+1)²
- A085880 → (θ+1)²
- A178821 → (θ+1)²
- A125092 → reverse → D
- A178822 → basis A013609 → (θ+1)²
- A038221 → basis A013609 → (θ+1)²
- A085880 → basis A013609 → (θ+1)²
- A156992 → basis A013609 → (θ+1)²
- A344565 → (θ+1)²
- A134346 → (θ+1)²
- A156992 → (θ+1)²
- A196347 → basis A013609 → (θ+1)²
- A003506 → (θ+1)²
- A178822 → (θ+1)²
- A038208 → (θ+1)²
- A085881 → basis A013609 → (θ+1)²
- A356546 → basis A013609 → (θ+1)²
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.