A374860 Obverse convolution (1)**A000201; see Comments.

1, 2, 8, 40, 280, 2520, 25200, 302400, 3931200, 58968000, 1002456000, 18044208000, 360884160000, 7939451520000, 182607384960000, 4565184624000000, 118694800224000000, 3323454406272000000, 99703632188160000000, 3090812597832960000000, 101996815728487680000000

Offset: 0

Author

Clark Kimberling, Aug 18 2024

Keywords

• nonn

Comments

See A374848 for the definition of obverse convolution and a guide to related sequences. a(n+1)/a(n) is an integer for n>=0, so (a(n)) is a divisibility sequence.

A000201 is assumed to start with a(0) = 0.

Crossrefs

Cf. A000012, A000201, A001622, A374848, A026351.

Programs

Mathematica

r = GoldenRatio;
s[n_] := 1; t[n_] := Floor[n*r];
u[n_] := Product[s[k] + t[n - k], {k, 0, n}]
Table[u[n], {n, 0, 20}]

Formula

a(n) = Product_{k=0..n} A026351(k).