A133087 → x ↦ x+1

nonnegative coefficients only rational roots

Proved for all n: all roots real, in (−∞, −1] · coefficients of one sign · Hadamard kernel what this means

Recurrence
\(P_{n}(x) = \left(8 + 3\,x - 5\,n - 2\,n x\right)\,P_{n-1}(x) + \left(10 + 9\,x + 2\,x^{2}\right)\,P_{n-1}'(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1314
24419
312167136
41632248181
54811210448111324
66419224016060121729
7192640912720340961512916
825610241792179211204481121616561
97683328640071685152246478416019126244
10102451201152015360134408064336096018020159049
11307216384396805760055680376321814462401500240231236196
1240962457667584112640126720101376591362534479201760264241531441
131228877824227328405504492800430848278784135168491041320025523362712125764
141638411468837273674547210250241025024768768439296192192640641601629123642814782969

Generated b-files: A133125 (row sums) ?

Computed in your browser ?

Other recurrences

Image under the basis map A007318 · proved equal for all n (proof step)

\(P_{n}(x) = \left(4 + 4\,x + x^{2}\right)\,P_{n-2}(x)\)
\(P_{0}(x) = 1\)
\(P_{1}(x) = 3 + x\)
Technical details
Node id
n-e5da0d00f07fcbc3 · revision 1 · JSON
Definition source
derived:shift_x_plus_one
derived:basis_map_A007318 (equal by e-dcae3f88ad03ec5b)
Fingerprint
f6-6c06ab9d9924dc09

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

OEIS matches ?

A generated b-file is computed from the node's definition along the row alignment of its OEIS link and starts at the entry's offset. It is an identification on a finite prefix, not a proof that the node and the OEIS entry agree for every n.

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:   1;
  1:   3,    1;
  2:   4,    4,    1;
  3:  12,   16,    7,    1;
  4:  16,   32,   24,    8,    1;
  5:  48,  112,  104,   48,   11,    1;
  6:  64,  192,  240,  160,   60,   12,   1;
  7: 192,  640,  912,  720,  340,   96,  15,   1;
  8: 256, 1024, 1792, 1792, 1120,  448, 112,  16,  1;
  9: 768, 3328, 6400, 7168, 5152, 2464, 784, 160, 19, 1;
%F Formula
The row polynomials satisfy P(n,x) = -(5*n-8+(2*n-3)*x)*P(n-1,x) + (10+9*x+2*x^2)*d/dx 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[-(5*n - 8 + (2*n - 3)*x)*P[n - 1, x] + (10 + 9*x + 2*x^2)*D[P[n - 1, x], x]];
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] = -(5*n - 8 + (2*n - 3)*x)*v[i - 1] + (10 + 9*x + 2*x^2)*deriv(v[i - 1], x)); 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, -1]
    Every polynomial of the sequence has only real roots, inside the stated interval.
    by the cited steps: e-52dd73548014190c
  • 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-52dd73548014190c, e-f0f6d4d5dc8cc42f
  • 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-52dd73548014190c, e-f0f6d4d5dc8cc42f
  • 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-f0f6d4d5dc8cc42f

Proof chains

3 incoming proof steps. 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.