basis-map coefficients of A021012 → θ+1 → basis A013609

only rational roots

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

Recurrence

\(P_{n}(x) = \left(-n - 2\,n x\right)\,P_{n-1}(x)\)
\(P_{1}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
111
2-2-4-6
36242454
4-24-144-288-192-648
51209602880384019209720
6-720-7200-28800-57600-57600-23040-174960
750406048030240080640012096009676803225603674160
8-40320-564480-3386880-11289600-22579200-27095040-18063360-5160960-88179840
9362880580608040642560162570240406425600650280960650280960371589120928972802380855680
10-3628800-65318400-522547200-2438553600-7315660800-14631321600-19508428800-16721510400-8360755200-1857945600-71425670400
1139916800798336000718502400038320128000134120448000321889075200536481792000613122048000459841536000204374016000408748032002357047123200
12-479001600-10538035200-105380352000-632282112000-2529128448000-7081559654400-14163119308800-20233027584000-20233027584000-13488685056000-5395474022400-980995276800-84853696435200
13622702080014944849920016439334912001095955660800049318004736000157817615155200368241102028800631270460620800789088075776000701411622912000420846973747200153035263180800255058771968003309294160972800
14-87178291200-2266635571200-27199626854400-199463930265600-997319651328000-3590350744780800-9574268652748800-19148537305497600-28722805958246400-31914228842496000-25531383073996800-13926208949452800-4642069649817600-714164561510400-138990354760857600
1513076743680003661488230400047599346995200038079477596160002094371267788800083774850711552000251324552134656000574456119164928000100529820853862400013403976113848320001340397611384832000974834626461696000487417313230848000149974557917184000214249368453120006254565964238592000
Technical details
Node id
n-37b2531d61071c9f · revision 0 · JSON
Definition source
derived:basis_map_A013609
Fingerprint
f6-11aec07ce60b6d61

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): yes

Matches ?

No OEIS matches.

Submission text ?

Atlas rows n = 1, …, ascending powers of x
%e Example
Triangle begins:
   1:        1;
   2:       -2,        -4;
   3:        6,        24,         24;
   4:      -24,      -144,       -288,        -192;
   5:      120,       960,       2880,        3840,        1920;
   6:     -720,     -7200,     -28800,      -57600,      -57600,       -23040;
   7:     5040,     60480,     302400,      806400,     1209600,       967680,       322560;
   8:   -40320,   -564480,   -3386880,   -11289600,   -22579200,    -27095040,    -18063360,     -5160960;
   9:   362880,   5806080,   40642560,   162570240,   406425600,    650280960,    650280960,    371589120,    92897280;
  10: -3628800, -65318400, -522547200, -2438553600, -7315660800, -14631321600, -19508428800, -16721510400, -8360755200, -1857945600;
%F Formula
The row polynomials satisfy P(n,x) = -(n+2*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 + 2*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 + 2*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.