A336971 G.f. A(x) satisfies: A(x) = 1 - x^3 * A(x/(1 - x)) / (1 - x).

1, 0, 0, -1, -1, -1, 0, 4, 15, 40, 86, 134, 16, -1060, -6119, -25187, -86678, -250846, -537819, -175233, 6998009, 55632942, 310923272, 1465146781, 6011047682, 20719304348, 49356093300, -36579100806, -1549214884054, -13807417413199, -92912464763743

Offset

0,8

Links

Seiichi Manyama, Table of n, a(n) for n = 0..704

Formula

a(0) = 1, a(1) = a(2) = 0; a(n) = -Sum_{k=0..n-3} binomial(n-3,k) * a(k).

Mathematica

nmax = 30; A[_] = 0; Do[A[x_] = 1 - x^3 A[x/(1 - x)]/(1 - x) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
a[0] = 1; a[n_] := a[n] = -Sum[Binomial[n - 3, k] a[k], {k, 0, n - 3}]; Table[a[n], {n, 0, 30}]

Crossrefs

Cf. A000587, A000996, A336970.

Sequence in context: A336995 A053698 A162867 * A059140 A031164 A116600

Adjacent sequences: A336968 A336969 A336970 * A336972 A336973 A336974

Keyword

sign

Author

Ilya Gutkovskiy, Aug 09 2020

Status

approved