basis-map coefficients of A021012 → θ+1 → basis A007318

palindromiconly rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
111
2-2-2-4
3612624
4-24-72-72-24-192
51204807204801201920
6-720-3600-7200-7200-3600-720-23040
75040302407560010080075600302405040322560
8-40320-282240-846720-1411200-1411200-846720-282240-40320-5160960
936288029030401016064020321280254016002032128010160640290304036288092897280
10-3628800-32659200-130636800-304819200-457228800-457228800-304819200-130636800-32659200-3628800-1857945600
1139916800399168000179625600047900160008382528000100590336008382528000479001600017962560003991680003991680040874803200
12-479001600-5269017600-26345088000-79035264000-158070528000-221298739200-221298739200-158070528000-79035264000-26345088000-5269017600-479001600-980995276800
13622702080074724249600410983372800136994457600030823752960004931800473600575376721920049318004736003082375296000136994457600041098337280074724249600622702080025505877196800
14-87178291200-1133317785600-6799906713600-24932991283200-62332478208000-112198460774400-149597947699200-149597947699200-112198460774400-62332478208000-24932991283200-6799906713600-1133317785600-87178291200-714164561510400
15130767436800018307441152000118998367488000475993469952000130898204236800026179640847360003926946127104000448793843097600039269461271040002617964084736000130898204236800047599346995200011899836748800018307441152000130767436800021424936845312000
Technical details
Node id
n-e08712dca818d9a6 · revision 0 · JSON
Definition source
derived:shift_x_plus_one
Fingerprint
f6-77a7ed3b1d5f257e

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: yes
  • 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): yes

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,        12,          6;
   4:      -24,       -72,        -72,        -24;
   5:      120,       480,        720,        480,        120;
   6:     -720,     -3600,      -7200,      -7200,      -3600,       -720;
   7:     5040,     30240,      75600,     100800,      75600,      30240,       5040;
   8:   -40320,   -282240,    -846720,   -1411200,   -1411200,    -846720,    -282240,     -40320;
   9:   362880,   2903040,   10160640,   20321280,   25401600,   20321280,   10160640,    2903040,    362880;
  10: -3628800, -32659200, -130636800, -304819200, -457228800, -457228800, -304819200, -130636800, -32659200, -3628800;
%F Formula
The row polynomials satisfy P(n,x) = -(n+n*x)*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]];
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]); 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. [Bra15] Petter Brändén. Unimodality, log-concavity, real-rootedness and beyond. Handbook of enumerative combinatorics, :437–483, March 2015. doi:10.1201/b18255-10
  2. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.