basis-map coefficients of A026729 → basis A056242 → D+1

nonnegative coefficients

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

Recurrence
\(\left(-6\,x - 8\,x^{2} + 4\,x^{3} + n + 6\,n x + 12\,n x^{2} - 4\,n x^{3} - 2\,n^{2} - 4\,n^{2} x^{2} + n^{3}\right)\,P_{n}(x) = \left(-2\,x - 12\,x^{2} + 12\,x^{3} - 8\,x^{4} - n + 20\,n x^{2} - 12\,n x^{3} + 6\,n^{2} x - 4\,n^{2} x^{2} + n^{3}\right)\,P_{n-1}(x) + \left(-4\,x^{2} - 4\,x^{3} - 8\,x^{4} - 8\,x^{5} - 2\,n x - 2\,n x^{2} - 8\,n x^{3} - 8\,n x^{4} + 2\,n^{2} x + 2\,n^{2} x^{2}\right)\,P_{n-1}'(x)\)
\(P_{1}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
111
2325
3613423
4104140899
5159617310816408
621190523594272321632
728337128622011816656646388
8365532758646579685152153612824596
945856536216248272092612013872352025693488
105512669678364687837110165079792359367936512351664
116618051647675078199294330005348540231216903681766410241311536
1278249726752144342460482937305125892011200726430722219523891220484856432
13913368417672624609857212400520394896544545483421280173081653478484992409617873408
14105444663089455598198212356587701109935515291234148542401003180845350401268224184320819265436544
15120576192638760383378263612460175285588304678590555380080472113602844224011619584296755239731216384238480960

Computed in your browser ?

Technical details
Node id
n-264767197e69db61 · revision 1 · JSON
Definition source
derived:one_plus_derivative
Fingerprint
f6-9c5a3526c6b32cef

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 -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): no

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 = 1, …, ascending powers of x
%e Example
Triangle begins:
   1:  1;
   2:  3,    2;
   3:  6,   13,    4;
   4: 10,   41,   40,     8;
   5: 15,   96,  173,   108,    16;
   6: 21,  190,  523,   594,   272,     32;
   7: 28,  337, 1286,  2201,  1816,    656,    64;
   8: 36,  553, 2758,  6465,  7968,   5152,  1536,   128;
   9: 45,  856, 5362, 16248, 27209,  26120, 13872,  3520,  256;
  10: 55, 1266, 9678, 36468, 78371, 101650, 79792, 35936, 7936, 512;
%F Formula
The row polynomials satisfy (n^3-2*n^2+n+(6*n-6)*x-(4*n^2-12*n+8)*x^2-(4*n-4)*x^3)*P(n,x) = (n^3-n+(6*n^2-2)*x-(4*n^2-20*n+12)*x^2-(12*n-12)*x^3-8*x^4)*P(n-1,x) + ((2*n^2-2*n)*x+(2*n^2-2*n-4)*x^2-(8*n+4)*x^3-(8*n+8)*x^4-8*x^5)*d/dx P(n-1,x) for n >= 2, with P(1,x) = 1.
%t Mathematica
P[1, x_] := 1;
P[n_, x_] := P[n, x] = Expand[Together[((n^3 - n + (6*n^2 - 2)*x - (4*n^2 - 20*n + 12)*x^2 - (12*n - 12)*x^3 - 8*x^4)*P[n - 1, x] + ((2*n^2 - 2*n)*x + (2*n^2 - 2*n - 4)*x^2 - (8*n + 4)*x^3 - (8*n + 8)*x^4 - 8*x^5)*D[P[n - 1, x], x])/(n^3 - 2*n^2 + n + (6*n - 6)*x - (4*n^2 - 12*n + 8)*x^2 - (4*n - 4)*x^3)]];
Table[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N)); v[1] = 1; for(n = 2, N, my(i = n); v[i] = ((n^3 - n + (6*n^2 - 2)*x - (4*n^2 - 20*n + 12)*x^2 - (12*n - 12)*x^3 - 8*x^4)*v[i - 1] + ((2*n^2 - 2*n)*x + (2*n^2 - 2*n - 4)*x^2 - (8*n + 4)*x^3 - (8*n + 8)*x^4 - 8*x^5)*deriv(v[i - 1], x))/(n^3 - 2*n^2 + n + (6*n - 6)*x - (4*n^2 - 12*n + 8)*x^2 - (4*n - 4)*x^3)); 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)

Generated with polytool c48629374597.

Proved properties

  • Real-rooted. Every row P_n, n >= 1, 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-a682124e3a957353
  • Coefficients of one sign. Every nonzero row, n >= 1: 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-a682124e3a957353
  • Hadamard kernel (Malo). Rows P_n, n >= 1, 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-a682124e3a957353

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