A038330 → reverse

nonnegative coefficientsonly rational roots

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

Recurrence

\(P_{n}(x) = \left(4 + 12\,x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 16 + 96\,x + 144\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9Pn(1)
01696144256
164576172817284096
2256307213824276482073665536
3102415360921602764804147202488321048576
4409673728552960221184049766405971968298598416777216
51638434406430965761548288046448640836075528360755235831808268435456
66553615728641651507299090432371589120891813888133772083211466178564299816964294967296
726214470778888493465659454259226754416648026324992160526499842063912140815479341056515978035268719476736
Technical details
Node id
n-b9fb6cd7175489e6 · revision 0 · JSON
Definition source
derived:reversal
Fingerprint
f6-f9762973ec1089d7

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 2)
  • 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:      16,        96,        144;
  1:      64,       576,       1728,        1728;
  2:     256,      3072,      13824,       27648,        20736;
  3:    1024,     15360,      92160,      276480,       414720,       248832;
  4:    4096,     73728,     552960,     2211840,      4976640,      5971968,       2985984;
  5:   16384,    344064,    3096576,    15482880,     46448640,     83607552,      83607552,      35831808;
  6:   65536,   1572864,   16515072,    99090432,    371589120,    891813888,    1337720832,    1146617856,     429981696;
  7:  262144,   7077888,   84934656,   594542592,   2675441664,   8026324992,   16052649984,   20639121408,   15479341056,    5159780352;
  8: 1048576,  31457280,  424673280,  3397386240,  17836277760,  64210599936,  160526499840,  275188285440,  309586821120,  206391214080,   61917364224;
  9: 4194304, 138412032, 2076180480, 18685624320, 112113745920, 470877732864, 1412633198592, 3027071139840, 4540606709760, 4540606709760, 2724364025856, 743008370688;
%F Formula
The row polynomials satisfy P(n,x) = (4+12*x)*P(n-1,x) for n >= 1, with P(0,x) = 16 + 96*x + 144*x^2.
%t Mathematica
P[0, x_] := 16 + 96*x + 144*x^2;
P[n_, x_] := P[n, x] = Expand[(4 + 12*x)*P[n - 1, x]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 16 + 96*x + 144*x^2; for(n = 1, N, my(i = n + 1); v[i] = (4 + 12*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 - 1, v[i])))};
T(9)

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. [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.