A052553 → Veronese 2 → x ↦ x+1

nonnegative coefficients

Proved for all n all roots real, in (−∞, −1]coefficients of one signHadamard kernel

Recurrence

\(P_{n}(x) = \left(1 + x\right)\,P_{n-4}(x) + \left(-1\right)\,P_{n-2}(x) + \left(2\right)\,P_{n-1}(x)\)
\(P_{1}(x) = 1\)
\(P_{2}(x) = 1\)
\(P_{3}(x) = 1\)
\(P_{4}(x) = 1\)

Rows ?

nx0x1x2x3Pn(1)
111
211
311
411
5213
6437
77613
8111021
91717135
102731563
11445815117
127210635213
13117188731379
141893281477671
15305570294281197
Technical details
Node id
n-4a08d50eedd2c85f · revision 0 · JSON
Definition source
derived:shift_x_plus_one
Fingerprint
f6-7b01bf956bad76c1

Observed on the stored rows ?

  • Degrees: 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3 (irregular)
  • 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): no

Matches ?

No OEIS matches.

Submission text ?

Atlas rows n = 1, …, ascending powers of x
%e Example
Triangle begins:
   1:  1;
   2:  1;
   3:  1;
   4:  1;
   5:  2,  1;
   6:  4,  3;
   7:  7,  6;
   8: 11, 10;
   9: 17, 17, 1;
  10: 27, 31, 5;
%F Formula
The row polynomials satisfy P(n,x) = (1+x)*P(n-4,x) - P(n-2,x) + 2*P(n-1,x) for n >= 5, with P(1,x) = 1, P(2,x) = 1, P(3,x) = 1, P(4,x) = 1.
%t Mathematica
P[1, x_] := 1;
P[2, x_] := 1;
P[3, x_] := 1;
P[4, x_] := 1;
P[n_, x_] := P[n, x] = Expand[(1 + x)*P[n - 4, x] - P[n - 2, x] + 2*P[n - 1, x]];
Table[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N)); v[1] = 1; v[2] = 1; v[3] = 1; v[4] = 1; for(n = 5, N, my(i = n); v[i] = (1 + x)*v[i - 4] - v[i - 2] + 2*v[i - 1]); 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

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. [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
  4. [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
  5. [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