A124860 → basis A008277

nonnegative coefficients

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

Recurrence

\(P_{n}(x) = \left(8 + 10\,x + 2\,x^{2}\right)\,P_{n-2}(x) + \left(10\,x + 4\,x^{2}\right)\,P_{n-2}'(x) + \left(2\,x^{2}\right)\,P_{n-2}''(x) + \left(2 + x\right)\,P_{n-1}(x) + \left(x\right)\,P_{n-1}'(x)\)
\(P_{0}(x) = 1\)
\(P_{1}(x) = 2 + x\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1213
21215330
34095455185
4176715605154111661
56724431598526254202114154
6275228595580933913010535116143140309
710880175015515865501585202300368902975851445595
8437761078155450328560831543450951926478122094752417116215588
9174592653731138070945696339055342106019814487379533037851018414341191844895
1069939239631075318107933773613610781464695384808347100501401144249601126950443956832414423441
112795520239010135262220458583662228651091680590069451582202375898525460314855513513003228225105105136531983096600
1211186176144017919521463516165889392043541477882315911191094407365192370554813042240068194836913717378718589822592457902731445849090935
134473651286618613911745565235059321483839851950979930900196274922143310688024547203385457389606503995297877186429325630454832435059956794454616509835416803
141789624325206540795514139053537739671482310490252783701720553138332210313321028262854599823218186648019780716298202999175078902895302810417593676106460954512998371092399368536484646
Technical details
Node id
n-8d1df120dd7721cd · revision 0 · JSON
Definition source
derived:basis_map_A008277
Fingerprint
f6-b5f1389370a379f1

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): 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 = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:      1;
  1:      2,       1;
  2:     12,      15,        3;
  3:     40,      95,       45,        5;
  4:    176,     715,      605,      154,       11;
  5:    672,    4431,     5985,     2625,      420,       21;
  6:   2752,   28595,    58093,    39130,    10535,     1161,      43;
  7:  10880,  175015,   515865,   501585,   202300,    36890,    2975,     85;
  8:  43776, 1078155,  4503285,  6083154,  3450951,   926478,  122094,   7524,   171;
  9: 174592, 6537311, 38070945, 69633905, 53421060, 19814487, 3795330, 378510, 18414, 341;
%F Formula
The row polynomials satisfy P(n,x) = (8+10*x+2*x^2)*P(n-2,x) + (10*x+4*x^2)*d/dx P(n-2,x) + 2*x^2*d^2/dx^2 P(n-2,x) + (2+x)*P(n-1,x) + x*d/dx P(n-1,x) for n >= 2, with P(0,x) = 1, P(1,x) = 2 + x.
%t Mathematica
P[0, x_] := 1;
P[1, x_] := 2 + x;
P[n_, x_] := P[n, x] = Expand[(8 + 10*x + 2*x^2)*P[n - 2, x] + (10*x + 4*x^2)*D[P[n - 2, x], x] + 2*x^2*D[P[n - 2, x], {x, 2}] + (2 + x)*P[n - 1, x] + x*D[P[n - 1, x], x]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 1; v[2] = 2 + x; for(n = 2, N, my(i = n + 1); v[i] = (8 + 10*x + 2*x^2)*v[i - 2] + (10*x + 4*x^2)*deriv(v[i - 2], x) + 2*x^2*deriv(deriv(v[i - 2], x), x) + (2 + x)*v[i - 1] + x*deriv(v[i - 1], x)); 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. [Bra15] Petter Brändén. Unimodality, log-concavity, real-rootedness and beyond. Handbook of enumerative combinatorics, :437–483, March 2015. doi:10.1201/b18255-10
  2. [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
  3. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.