basis-map coefficients of A112227 → θ+1 → basis A013609

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(1 + n\right)\,P_{n}(x) = \left(2 + 4\,x + n + 2\,n x\right)\,P_{n-1}(x)\)
\(P_{1}(x) = 3 + 12\,x + 12\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14x15x16Pn(1)
13121227
24244832108
354012016080405
46602404804801921458
57844201120168013444485103
681126722240448053763584102417496
79144100840321008016128161289216230459049
8101801440672020160403205376046080230405120196830
91122019801056036960887041478401689601267205632011264649539
101226426401584063360177408354816506880506880337920135168245762125764
1113312343222880102960329472768768131788816473601464320878592319488532486908733
121436443683203216016057657615375363075072461260851251204100096223641674547211468822320522
131542054604368024024096096028828806589440115315201537536015375360111820805591040172032024576071744535
141648067205824034944015375365125120131788802635776041000960492011524472832029818880137625603932160524288229582512
151754481607616049504023761928712704248934405601024099573760139403264152076288126730240779878403342336089128961114112731794257
Technical details
Node id
n-660b73dc06a54453 · revision 0 · JSON
Definition source
derived:basis_map_A013609
Fingerprint
f6-11aec07ce60b6d61

Observed on the stored rows ?

  • Degrees: 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 (affine: slope 1, intercept 1)
  • 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 = 1, …, ascending powers of x
%e Example
Triangle begins:
   1:  3,  12,   12;
   2:  4,  24,   48,    32;
   3:  5,  40,  120,   160,    80;
   4:  6,  60,  240,   480,   480,    192;
   5:  7,  84,  420,  1120,  1680,   1344,    448;
   6:  8, 112,  672,  2240,  4480,   5376,   3584,   1024;
   7:  9, 144, 1008,  4032, 10080,  16128,  16128,   9216,   2304;
   8: 10, 180, 1440,  6720, 20160,  40320,  53760,  46080,  23040,   5120;
   9: 11, 220, 1980, 10560, 36960,  88704, 147840, 168960, 126720,  56320,  11264;
  10: 12, 264, 2640, 15840, 63360, 177408, 354816, 506880, 506880, 337920, 135168, 24576;
%F Formula
The row polynomials satisfy (n+1)*P(n,x) = (n+2+(2*n+4)*x)*P(n-1,x) for n >= 2, with P(1,x) = 3 + 12*x + 12*x^2.
%t Mathematica
P[1, x_] := 3 + 12*x + 12*x^2;
P[n_, x_] := P[n, x] = Expand[Together[((n + 2 + (2*n + 4)*x)*P[n - 1, x])/(n + 1)]];
Table[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N)); v[1] = 3 + 12*x + 12*x^2; for(n = 2, N, my(i = n); v[i] = ((n + 2 + (2*n + 4)*x)*v[i - 1])/(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

Proof chains ? JSON

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. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.