basis-map coefficients of A030528, shifted → (θ+1)² → basis A008277

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

Recurrence

\(\left(n^{2}\right)\,P_{n}(x) = \left(-1 - x - 2\,n - 2\,n x - n^{2} - n^{2} x\right)\,P_{n-1}(x) + \left(-x - 2\,n x - n^{2} x\right)\,P_{n-1}'(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7Pn(1)
011
1-4-4-8
2927945
3-16-112-96-16-240
425375625250251300
5-36-1116-3240-2340-540-36-7308
64930871474917150686010294942973
7-64-8128-61824-108864-67200-17024-1792-64-264960
Technical details
Node id
n-935ddceb0de996bf · revision 0 · JSON
Definition source
derived:basis_map_A008277
Fingerprint
f6-4732d0911d5a78c5

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): 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 = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:    1;
  1:   -4,     -4;
  2:    9,     27,       9;
  3:  -16,   -112,     -96,      -16;
  4:   25,    375,     625,      250,       25;
  5:  -36,  -1116,   -3240,    -2340,     -540,      -36;
  6:   49,   3087,   14749,    17150,     6860,     1029,      49;
  7:  -64,  -8128,  -61824,  -108864,   -67200,   -17024,   -1792,    -64;
  8:   81,  20655,  245025,   629370,   563031,   214326,   37422,   2916,    81;
  9: -100, -51100, -933000, -3410500, -4252500, -2282700, -588000, -75000, -4500, -100;
%F Formula
The row polynomials satisfy n^2*P(n,x) = -(n^2+2*n+1+(n^2+2*n+1)*x)*P(n-1,x) - (n^2+2*n+1)*x*d/dx P(n-1,x) for n >= 1, with P(0,x) = 1.
%t Mathematica
P[0, x_] := 1;
P[n_, x_] := P[n, x] = Expand[Together[(-(n^2 + 2*n + 1 + (n^2 + 2*n + 1)*x)*P[n - 1, x] - (n^2 + 2*n + 1)*x*D[P[n - 1, x], x])/(n^2)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(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 + 2*n + 1)*x)*v[i - 1] - (n^2 + 2*n + 1)*x*deriv(v[i - 1], x))/(n^2)); 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]
  • Coefficients of one sign? Every nonzero row, n ≥ 0: the coefficients of P_n have one sign
    derived from Ray basis map theorem
  • Hadamard kernel (Malo)? Rows P_n, n ≥ 0, are Hadamard kernels (preserve real-rootedness)
    derived from Ray basis map theorem

Proof chains ? JSON

Same fingerprint ?

References

  1. [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
  2. [Bra15] Petter Brändén. Unimodality, log-concavity, real-rootedness and beyond. Handbook of enumerative combinatorics, :437–483, March 2015. doi:10.1201/b18255-10
  3. [MW08] Shi-Mei Ma and Yi Wang. q-Eulerian polynomials and polynomials with only real zeros. The Electronic Journal of Combinatorics, 15(1):Research Paper 17, January 2008. doi:10.37236/741
  4. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.