basis-map coefficients of A127647 → basis A008277

nonnegative coefficients

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

Recurrence

\(P_{n}(x) = \left(4 + 5\,x + x^{2}\right)\,P_{n-2}(x) + \left(5\,x + 2\,x^{2}\right)\,P_{n-2}'(x) + \left(x^{2}\right)\,P_{n-2}''(x) + \left(2 + x\right)\,P_{n-1}(x) + \left(x\right)\,P_{n-1}'(x)\)
\(P_{0}(x) = 1\)
\(P_{1}(x) = 2 + x\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1213
2810220
32457273111
480325275705755
525616882280100016085392
68328645175631183031853511342419
726884323912744912392149980911473521357147
887042143708953901209516686154184212242761496343224152
9281601054405614047511231275861630031958856121506105029705530942725
109113651642254145183910080763010183068550143401130960831879680146850578589314617403
11294912252142562766281768825905441151663040732676032250644240485606885417280340560110881443374040960
1295436812287138518311970957588002422126088092131016202844844299609641112721324166228491148269557663372097023338038388205
13308838459797138712050505285643508406451346858513001354983439817378475104023371496720449003154653285632438869831168104339208377449406327071
149994240290761685078960200110540108414300141168230385017526161753101174333089930459730013600110466327400167490323001616895280982527003608150725906105549281997220
Technical details
Node id
n-e14a0299f56ab327 · 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:     8,      10,       2;
  3:    24,      57,      27,        3;
  4:    80,     325,     275,       70,       5;
  5:   256,    1688,    2280,     1000,     160,       8;
  6:   832,    8645,   17563,    11830,    3185,     351,     13;
  7:  2688,   43239,  127449,   123921,   49980,    9114,    735,    21;
  8:  8704,  214370,  895390,  1209516,  686154,  184212,  24276,  1496,   34;
  9: 28160, 1054405, 6140475, 11231275, 8616300, 3195885, 612150, 61050, 2970, 55;
%F Formula
The row polynomials satisfy P(n,x) = (4+5*x+x^2)*P(n-2,x) + (5*x+2*x^2)*d/dx P(n-2,x) + 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[(4 + 5*x + x^2)*P[n - 2, x] + (5*x + 2*x^2)*D[P[n - 2, x], x] + 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] = (4 + 5*x + x^2)*v[i - 2] + (5*x + 2*x^2)*deriv(v[i - 2], x) + 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.