A022654 Expansion of Product_{m>=1} (1+m*q^m)^26.

1, 26, 377, 4030, 35282, 267020, 1804855, 11133278, 63635364, 340845830, 1725623406, 8314033858, 38329313893, 169845329890, 726114272520, 3004404814658, 12063899757390, 47120073874016, 179388891204380, 666854279935844, 2424357631391397, 8631804737992852

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..1000

Maple

b:= proc(n) option remember; `if`(n=0, 1, add(
      26*(-d)^(n/d+1), d=numtheory[divisors](n)))
    end:
a:= proc(n) option remember; `if`(n=0, 1,
       add(b(j)*a(n-j), j=1..n)/n)
    end:
seq(a(n), n=0..30);  # Alois P. Heinz, Jul 18 2018

Mathematica

With[{nmax=50}, CoefficientList[Series[Product[(1+m*q^m)^26, {m, 1, nmax}], {q, 0, nmax}], q]] (* G. C. Greubel, Jul 18 2018 *)

Prog

(PARI) m=50; q='q+O('q^m); Vec(prod(n=1, m, (1+n*q^n)^26)) \\ G. C. Greubel, Jul 18 2018
(Magma) Coefficients(&*[(1+m*x^m)^26:m in [1..40]])[1..50] where x is PolynomialRing(Integers()).1; // G. C. Greubel, Jul 18 2018

Crossrefs

Column k=26 of A297321.

Sequence in context: A364010 A004414 A125461 * A183187 A004318 A159882

Adjacent sequences: A022651 A022652 A022653 * A022655 A022656 A022657

Keyword

nonn

Author

N. J. A. Sloane

Status

approved