basis-map coefficients of A026729, shifted → θ+1 → basis A008277

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
111
2-2-2-4
339315
4-4-28-24-4-60
5575125505260
6-6-186-540-390-90-6-1218
774412107245098014776139
8-8-1016-7728-13608-8400-2128-224-8-33120
9922952722569930625592381441583249190323
10-10-5110-93300-341050-425250-228270-58800-7500-450-10-1159750
11111125331351116032502714030197435770385713068012705605117464270
12-12-24564-1038312-7338012-16552800-15883824-7528752-1908324-267300-20460-792-12-50563164
131353235340112532922890976105131211770567430051224694956467352651122531603101413359377681
14-14-114674-11045580-145484430-561050490-888109222-690609920-292772480-71891820-10538528-924924-47138-1274-14-2672590508
151524574535626515635339250316150380063103990956131119995324941760010069273501899397502219217015970506825015751520744378175
Technical details
Node id
n-e07bac431cf09fed · 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:   3,     9,      3;
   4:  -4,   -28,    -24,      -4;
   5:   5,    75,    125,      50,       5;
   6:  -6,  -186,   -540,    -390,     -90,      -6;
   7:   7,   441,   2107,    2450,     980,     147,      7;
   8:  -8, -1016,  -7728,  -13608,   -8400,   -2128,   -224,    -8;
   9:   9,  2295,  27225,   69930,   62559,   23814,   4158,   324,    9;
  10: -10, -5110, -93300, -341050, -425250, -228270, -58800, -7500, -450, -10;
%F Formula
The row polynomials satisfy (n-1)*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[Together[(-(n + n*x)*P[n - 1, x] - n*x*D[P[n - 1, x], x])/(n - 1)]];
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))/(n - 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

  • 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.