A178821 → basis A007318 → reverse

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(n\right)\,P_{n}(x) = \left(4 + 8\,x + n + 2\,n x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
151015
2156060135
335210420280945
4705601680224011205670
5126126050401008010080403230618
621025201260033600504004032013440153090
73304620277209240018480022176014784042240721710
84957920554402217605544008870408870405068801267203247695
9715128701029604804801441440288288038438403294720164736036608014073345
10100120020180180960960336336080720641345344015375360115315205125120102502459108049
11136530030300300180180072072002018016040360320576576005765760038438400153753602795520241805655
1218204368048048032032001441440046126080107627520184504320230630400205004800123002880447283207454720967222620
1323806188074256054454402722720098017920261381120522762240784143360871270400697016320380190720126730240194969603794488740
1430608568011138408910720490089601960358405881075201344245760235243008031365734403136573440228114432011405721603509452805013504014635885140
Technical details
Node id
n-66e925f07bda356b · revision 0 · JSON
Definition source
derived:reversal
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 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): yes

Matches ?

No OEIS matches.

Submission text ?

Atlas rows n = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:   1;
  1:   5,    10;
  2:  15,    60,     60;
  3:  35,   210,    420,    280;
  4:  70,   560,   1680,   2240,    1120;
  5: 126,  1260,   5040,  10080,   10080,    4032;
  6: 210,  2520,  12600,  33600,   50400,   40320,   13440;
  7: 330,  4620,  27720,  92400,  184800,  221760,  147840,   42240;
  8: 495,  7920,  55440, 221760,  554400,  887040,  887040,  506880,  126720;
  9: 715, 12870, 102960, 480480, 1441440, 2882880, 3843840, 3294720, 1647360, 366080;
%F Formula
The row polynomials satisfy n*P(n,x) = (n+4+(2*n+8)*x)*P(n-1,x) for n >= 1, with P(0,x) = 1.
%t Mathematica
P[0, x_] := 1;
P[n_, x_] := P[n, x] = Expand[Together[((n + 4 + (2*n + 8)*x)*P[n - 1, x])/(n)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 1; for(n = 1, N, my(i = n + 1); v[i] = ((n + 4 + (2*n + 8)*x)*v[i - 1])/(n)); 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

Proof chains ? JSON

Candidate equalities ?

Same fingerprint ?

References

  1. [Bra06] Petter Brändén. On linear transformations preserving the Pólya frequency property. Transactions of the American Mathematical Society, 358(8):3697–3716, February 2006. doi:10.1090/s0002-9947-06-03856-6
  2. [Bra15] Petter Brändén. Unimodality, log-concavity, real-rootedness and beyond. Handbook of enumerative combinatorics, :437–483, March 2015. doi:10.1201/b18255-10
  3. [LW07] Lily L. Liu and Yi Wang. A unified approach to polynomial sequences with only real zeros. Advances in Applied Mathematics, 38(4):542–560, May 2007. doi:10.1016/j.aam.2006.02.003
  4. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.