basis-map coefficients of A145596 → D+1

Proved for all n: all roots real what this means

Recurrence
\(\left(20\,n - 16\,n x + 4\,n x^{2} - 3\,n^{2} + 4\,n^{2} x + n^{2} x^{2} + 2\,n^{3} + 2\,n^{3} x + n^{4}\right)\,P_{n}(x) = \left(16 - 2\,x - 4\,x^{2} + 2\,x^{3} + 16\,n + 13\,n x - 11\,n x^{2} + 5\,n x^{3} + 6\,n^{2} + 9\,n^{2} x - n^{2} x^{2} + 3\,n^{2} x^{3} + 4\,n^{3} - 3\,n^{3} x + 6\,n^{3} x^{2} - 2\,n^{4} + 3\,n^{4} x\right)\,P_{n-1}(x) + \left(-12 + 26\,x - 22\,x^{2} + 10\,x^{3} - 2\,x^{4} - 10\,n + 15\,n x - 9\,n x^{2} + 6\,n x^{3} - 2\,n x^{4} - 2\,n^{2} - 5\,n^{2} x + 11\,n^{2} x^{2} - 4\,n^{2} x^{3} - 4\,n^{3} + 6\,n^{3} x - 2\,n^{3} x^{2}\right)\,P_{n-1}'(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7Pn(1)
011
1224
208311
3-8820424
4-5-404540545
530-90-9015070676
628168-525-563851127119
7-112560168-18483928401688176

Generated b-files: A167875 (row sums) ?

Computed in your browser ?

Technical details
Node id
n-0506e8505d88de13 · revision 1 · JSON
Definition source
derived:one_plus_derivative
Fingerprint
f6-dfe2a78a64c01331

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): no
  • Only rational roots (rr_by_factors: every nonzero row is a product of linear factors over ℚ): no

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:    2,     2;
  2:    0,     8,    3;
  3:   -8,     8,   20,     4;
  4:   -5,   -40,   45,    40,      5;
  5:   30,   -90,  -90,   150,     70,     6;
  6:   28,   168, -525,   -56,    385,   112,    7;
  7: -112,   560,  168, -1848,    392,   840,  168,    8;
  8: -126,  -672, 3780, -2016,  -4620,  2016, 1638,  240,   9;
  9:  420, -2940,  840, 14280, -13440, -8400, 6300, 2940, 330, 10;
%F Formula
The row polynomials satisfy (n^4+2*n^3-3*n^2+20*n+(2*n^3+4*n^2-16*n)*x+(n^2+4*n)*x^2)*P(n,x) = -(2*n^4-4*n^3-6*n^2-16*n-16-(3*n^4-3*n^3+9*n^2+13*n-2)*x-(6*n^3-n^2-11*n-4)*x^2-(3*n^2+5*n+2)*x^3)*P(n-1,x) - (4*n^3+2*n^2+10*n+12-(6*n^3-5*n^2+15*n+26)*x+(2*n^3-11*n^2+9*n+22)*x^2+(4*n^2-6*n-10)*x^3+(2*n+2)*x^4)*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[(-(2*n^4 - 4*n^3 - 6*n^2 - 16*n - 16 - (3*n^4 - 3*n^3 + 9*n^2 + 13*n - 2)*x - (6*n^3 - n^2 - 11*n - 4)*x^2 - (3*n^2 + 5*n + 2)*x^3)*P[n - 1, x] - (4*n^3 + 2*n^2 + 10*n + 12 - (6*n^3 - 5*n^2 + 15*n + 26)*x + (2*n^3 - 11*n^2 + 9*n + 22)*x^2 + (4*n^2 - 6*n - 10)*x^3 + (2*n + 2)*x^4)*D[P[n - 1, x], x])/(n^4 + 2*n^3 - 3*n^2 + 20*n + (2*n^3 + 4*n^2 - 16*n)*x + (n^2 + 4*n)*x^2)]];
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] = (-(2*n^4 - 4*n^3 - 6*n^2 - 16*n - 16 - (3*n^4 - 3*n^3 + 9*n^2 + 13*n - 2)*x - (6*n^3 - n^2 - 11*n - 4)*x^2 - (3*n^2 + 5*n + 2)*x^3)*v[i - 1] - (4*n^3 + 2*n^2 + 10*n + 12 - (6*n^3 - 5*n^2 + 15*n + 26)*x + (2*n^3 - 11*n^2 + 9*n + 22)*x^2 + (4*n^2 - 6*n - 10)*x^3 + (2*n + 2)*x^4)*deriv(v[i - 1], x))/(n^4 + 2*n^3 - 3*n^2 + 20*n + (2*n^3 + 4*n^2 - 16*n)*x + (n^2 + 4*n)*x^2)); 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, +inf)
    Every polynomial of the sequence has only real roots, inside the stated interval.
    by the cited steps: e-2036104bf9bd843b

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. [Fav35] Jean Favard. Sur les polynômes de tchebicheff. C. R. Acad. Sci. Paris, 200:2052–2053, 1935.
  2. [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
  3. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.
  4. [Sze39] G. Szegő. Orthogonal Polynomials. Colloquium publications, American Mathematical Society, 1939. doi:10.1090/coll/023