A132774 → Veronese 2 (j=1) → D

palindromicγ-positivenonnegative coefficientsonly rational roots

Proved for all n all roots real, in (−∞, 0]coefficients of one signHadamard kernel

Recurrence

\(\left(360 - 342\,n + 119\,n^{2} - 18\,n^{3} + n^{4}\right)\,P_{n}(x) = \left(264\,x^{2} - 118\,n x^{2} - 11\,n^{2} x^{2} + 10\,n^{3} x^{2} - n^{4} x^{2}\right)\,P_{n-4}(x) + \left(96\,x^{3} - 56\,n x^{3} + 8\,n^{2} x^{3}\right)\,P_{n-4}'(x) + \left(-360\,x - 48\,n x + 114\,n^{2} x - 28\,n^{3} x + 2\,n^{4} x\right)\,P_{n-2}(x) + \left(-240\,x^{2} + 88\,n x^{2} - 8\,n^{2} x^{2}\right)\,P_{n-2}'(x)\)
\(P_{0}(x) = 0\)
\(P_{1}(x) = 0\)
\(P_{2}(x) = 0\)
\(P_{3}(x) = 7\)
\(P_{4}(x) = 8\)
\(P_{5}(x) = 22\,x\)
\(P_{6}(x) = 24\,x\)

Rows ?

nx0x1x2Pn(1)
00
10
20
377
488
502222
602424
7004545
Technical details
Node id
n-8db75f631150c8cb · revision 0 · JSON
Definition source
derived:derivative
Fingerprint
f6-edf6954a4cd8adfc

Observed on the stored rows ?

  • Degrees: -1, -1, -1, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5 (half affine: slope 1, intercept -3)
  • Palindromic rows: yes
  • γ-positive (gamma_positive): yes
  • 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 Example
Triangle begins:
  0: 0;
  1: 0;
  2: 0;
  3: 7;
  4: 8;
  5: 0, 22;
  6: 0, 24;
  7: 0,  0, 45;
  8: 0,  0, 48;
  9: 0,  0,  0, 76;
%F Formula
The row polynomials satisfy (n^4-18*n^3+119*n^2-342*n+360)*P(n,x) = -(n^4-10*n^3+11*n^2+118*n-264)*x^2*P(n-4,x) + (8*n^2-56*n+96)*x^3*d/dx P(n-4,x) + (2*n^4-28*n^3+114*n^2-48*n-360)*x*P(n-2,x) - (8*n^2-88*n+240)*x^2*d/dx P(n-2,x) for n >= 7, with P(0,x) = 0, P(1,x) = 0, P(2,x) = 0, P(3,x) = 7, P(4,x) = 8, P(5,x) = 22*x, P(6,x) = 24*x.
%t Mathematica
P[0, x_] := 0;
P[1, x_] := 0;
P[2, x_] := 0;
P[3, x_] := 7;
P[4, x_] := 8;
P[5, x_] := 22*x;
P[6, x_] := 24*x;
P[n_, x_] := P[n, x] = Expand[Together[(-(n^4 - 10*n^3 + 11*n^2 + 118*n - 264)*x^2*P[n - 4, x] + (8*n^2 - 56*n + 96)*x^3*D[P[n - 4, x], x] + (2*n^4 - 28*n^3 + 114*n^2 - 48*n - 360)*x*P[n - 2, x] - (8*n^2 - 88*n + 240)*x^2*D[P[n - 2, x], x])/(n^4 - 18*n^3 + 119*n^2 - 342*n + 360)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 0; v[2] = 0; v[3] = 0; v[4] = 7; v[5] = 8; v[6] = 22*x; v[7] = 24*x; for(n = 7, N, my(i = n + 1); v[i] = (-(n^4 - 10*n^3 + 11*n^2 + 118*n - 264)*x^2*v[i - 4] + (8*n^2 - 56*n + 96)*x^3*deriv(v[i - 4], x) + (2*n^4 - 28*n^3 + 114*n^2 - 48*n - 360)*x*v[i - 2] - (8*n^2 - 88*n + 240)*x^2*deriv(v[i - 2], x))/(n^4 - 18*n^3 + 119*n^2 - 342*n + 360)); 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

Proof chains ? JSON

Same fingerprint ?

References

  1. [ASW52] Michael Aissen, I. J. Schoenberg and A. M. Whitney. On the generating functions of totally positive sequences I. Journal d’Analyse Mathématique, 2(1):93–103, 1952. doi:10.1007/BF02786970
  2. [AW24] Christos A. Athanasiadis and David G. Wagner. Veronese sections and interlacing matrices of polynomials and formal power series. arXiv:2404.12989. arXiv
  3. [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
  4. [Bra15] Petter Brändén. Unimodality, log-concavity, real-rootedness and beyond. Handbook of enumerative combinatorics, :437–483, March 2015. doi:10.1201/b18255-10
  5. [Edr53] Albert Edrei. Proof of a Conjecture of Schoenberg on the Generating Function of a Totally Positive Sequence. Canadian Journal of Mathematics, 5:86–94, 1953. doi:10.4153/CJM-1953-010-3
  6. [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
  7. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.