A152842 → x ↦ x/(x+1)

nonnegative coefficients only rational roots

Proved for all n: all roots real, in [−1, 0] · coefficients of one sign · Hadamard kernel what this means

Recurrence
\(\left(1 + 3\,x + 3\,x^{2} + x^{3}\right)\,P_{n}(x) = \left(1 + x - 19\,x^{2} - 53\,x^{3} - 50\,x^{4} - 16\,x^{5} + 6\,n x + 34\,n x^{2} + 66\,n x^{3} + 54\,n x^{4} + 16\,n x^{5}\right)\,P_{n-1}(x) + \left(-2\,x - 18\,x^{2} - 58\,x^{3} - 86\,x^{4} - 60\,x^{5} - 16\,x^{6}\right)\,P_{n-1}'(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1145
216815
3110323275
4112529664225
51161003044482561125
6118132504105611525123375
71222041032307253765120204816875
812424814405136115201587212288409650625
91283442432108963206461952757765324816384253125
101304003120157605385612608019968020480012288032768759375
1113452047202824011689634150470400010035209420805242881310723796875
121365885760376801733765752961387008241152029491202408448117964826214411390625
131407328112607203240961268800368819279595521259520014204928108134404980736104857656953125
14142812957676944445536191699262257921533593628514304393953283922329626607616110100482097152170859375

Generated b-files: A101553 (row sums) ?

Computed in your browser ?

Technical details
Node id
n-c064f43b3483c251 · revision 1 · JSON
Definition source
derived:mobius_x_over_x_plus_one
Fingerprint
f6-5b8f1017b01dd220

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: 1,  4;
  2: 1,  6,   8;
  3: 1, 10,  32,   32;
  4: 1, 12,  52,   96,    64;
  5: 1, 16, 100,  304,   448,   256;
  6: 1, 18, 132,  504,  1056,  1152,   512;
  7: 1, 22, 204, 1032,  3072,  5376,  5120,  2048;
  8: 1, 24, 248, 1440,  5136, 11520, 15872, 12288,  4096;
  9: 1, 28, 344, 2432, 10896, 32064, 61952, 75776, 53248, 16384;
%F Formula
The row polynomials satisfy (1+3*x+3*x^2+x^3)*P(n,x) = (1+(6*n+1)*x+(34*n-19)*x^2+(66*n-53)*x^3+(54*n-50)*x^4+(16*n-16)*x^5)*P(n-1,x) - (2*x+18*x^2+58*x^3+86*x^4+60*x^5+16*x^6)*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[Together[((1 + (6*n + 1)*x + (34*n - 19)*x^2 + (66*n - 53)*x^3 + (54*n - 50)*x^4 + (16*n - 16)*x^5)*P[n - 1, x] - (2*x + 18*x^2 + 58*x^3 + 86*x^4 + 60*x^5 + 16*x^6)*D[P[n - 1, x], x])/(1 + 3*x + 3*x^2 + x^3)]];
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] = ((1 + (6*n + 1)*x + (34*n - 19)*x^2 + (66*n - 53)*x^3 + (54*n - 50)*x^4 + (16*n - 16)*x^5)*v[i - 1] - (2*x + 18*x^2 + 58*x^3 + 86*x^4 + 60*x^5 + 16*x^6)*deriv(v[i - 1], x))/(1 + 3*x + 3*x^2 + x^3)); 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 [-1, 0]
    Every polynomial of the sequence has only real roots, inside the stated interval.
    by the cited steps: e-ff2584c8c316f8a8
  • 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-ff2584c8c316f8a8
  • 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-ff2584c8c316f8a8

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

Same fingerprint (1)

Equal up to content, sign, reversal and a small index shift.