basis-map coefficients of A021012 → θ+1 → basis A008277

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7Pn(1)
111
2-2-2-4
3618630
4-24-168-144-24-360
51201800300012001206240
6-720-22320-64800-46800-10800-720-146160
750403175201517040176400070560010584050404420080
8-40320-5120640-38949120-68584320-42336000-10725120-1128960-40320-166924800
Technical details
Node id
n-cc237eefd2ad62b2 · 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 -1)
  • 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 = 1, …, ascending powers of x
%e Example
Triangle begins:
   1:        1;
   2:       -2,          -2;
   3:        6,          18,            6;
   4:      -24,        -168,         -144,           -24;
   5:      120,        1800,         3000,          1200,           120;
   6:     -720,      -22320,       -64800,        -46800,        -10800,         -720;
   7:     5040,      317520,      1517040,       1764000,        705600,       105840,         5040;
   8:   -40320,    -5120640,    -38949120,     -68584320,     -42336000,    -10725120,     -1128960,      -40320;
   9:   362880,    92534400,   1097712000,    2819577600,    2522378880,    960180480,    167650560,    13063680,     362880;
  10: -3628800, -1854316800, -33856704000, -123760224000, -154314720000, -82834617600, -21337344000, -2721600000, -163296000, -3628800;
%F Formula
The row polynomials satisfy P(n,x) = -(n+n*x)*P(n-1,x) - n*x*d/dx P(n-1,x) for n >= 2, with P(1,x) = 1.
%t Mathematica
P[1, x_] := 1;
P[n_, x_] := P[n, x] = Expand[-(n + n*x)*P[n - 1, x] - n*x*D[P[n - 1, x], x]];
Table[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N)); v[1] = 1; for(n = 2, N, my(i = n); v[i] = -(n + n*x)*v[i - 1] - n*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, v[i])))};
T(10)

polytool c48629374597

Properties

  • Real-rooted? Every row P_n, n ≥ 1, is zero or real-rooted with all roots in (−∞, 0]
  • Coefficients of one sign? Every nonzero row, n ≥ 1: the coefficients of P_n have one sign
    derived from Ray basis map theorem
  • Hadamard kernel (Malo)? Rows P_n, n ≥ 1, 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.