A038331 → basis A007318

nonnegative coefficients only rational roots

Proved for all n: all roots real, in (−∞, 0] · coefficients of one sign · Hadamard kernel what this means

Recurrence
\(P_{n}(x) = \left(17 + 5\,x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 289 + 170\,x + 25\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9Pn(1)
028917025484
149134335127512510648
28352198260433508500625234256
31419857208802512282503612505312531255153632
424137569425957103132037512282500270937531875015625113379904
5410338673844814915745424925365404375107471875189656251859375781252494357888
669757574411641354692016896298300993899900036540437508597750001264375001062500039062554875873536
71185878764973139090848453693048057002534444745001118137387503288639375064483125008128125005976562519531251207269217792

Computed in your browser ?

Technical details
Node id
n-4af84b2e19878bab · revision 1 · JSON
Definition source
derived:basis_map_A007318
Fingerprint
f6-75fb8f2b619cd489

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

OEIS matches ?

OEIS submission text ?

Fields to paste into an OEIS submission: the example %e, the formula %F and programs %t (Mathematica) and %o (PARI/GP) that list the same rows. For an OEIS link the row numbers, the offset and the orientation are those of the entry, as matched; the matched terms were compared with the published ones, which identifies the node with the entry on a finite prefix, not for every n. The PARI/GP program is not machine-checked here.

The atlas's own rows: n = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:            289,             170,              25;
  1:           4913,            4335,            1275,             125;
  2:          83521,           98260,           43350,            8500,            625;
  3:        1419857,         2088025,         1228250,          361250,          53125,           3125;
  4:       24137569,        42595710,        31320375,        12282500,        2709375,         318750,          15625;
  5:      410338673,       844814915,       745424925,       365404375,      107471875,       18965625,        1859375,         78125;
  6:     6975757441,     16413546920,     16896298300,      9938999000,     3654043750,      859775000,      126437500,      10625000,       390625;
  7:   118587876497,    313909084845,    369304805700,    253444474500,   111813738750,    32886393750,     6448312500,     812812500,     59765625,     1953125;
  8:  2015993900449,   5929393824850,   7847727121125,   6155080095000,  3168055931250,  1118137387500,   274053281250,   46059375000,   5080078125,   332031250,    9765625;
  9: 34271896307633, 110879664524695, 163058330183375, 143874997220625, 84632351306250, 34848615243750, 10249592718750, 2153275781250, 316658203125, 31044921875, 1826171875, 48828125;
%F Formula
The row polynomials satisfy P(n,x) = (17+5*x)*P(n-1,x) for n >= 1, with P(0,x) = 289 + 170*x + 25*x^2.
%t Mathematica
P[0, x_] := 289 + 170*x + 25*x^2;
P[n_, x_] := P[n, x] = Expand[(17 + 5*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] = 289 + 170*x + 25*x^2; for(n = 1, N, my(i = n + 1); v[i] = (17 + 5*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)

Generated with polytool c48629374597.

Proved properties

  • Real-rooted. Every row P_n, n >= 0, is zero or real-rooted with all roots in (-inf, 0]
    Every polynomial of the sequence has only real roots, inside the stated interval.
    by the cited steps: e-e0432c3ecb510b0f
  • Coefficients of one sign. Every nonzero row, n >= 0: the coefficients of P_n have one sign
    All coefficients of each polynomial have the same sign (after x -> -x when alternating).
    derived from the cited steps by a stated theorem: e-e0432c3ecb510b0f
  • Hadamard kernel (Malo). Rows P_n, n >= 0, are Hadamard kernels (preserve real-rootedness)
    Multiplying the coefficients of any real-rooted polynomial termwise by those of a row (Hadamard product) gives a real-rooted polynomial again.
    derived from the cited steps by a stated theorem: e-e0432c3ecb510b0f

Proof chains

1 incoming proof step. Each step is expanded back to the roots of the proof DAG, the theorem checks of a node's own rule. JSON

No candidate equalities or related sequences.

References

  1. [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