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

0,2

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.

Links

Table of n, a(n) for n=0..20.

Formula

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

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}]

Crossrefs

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

Sequence in context: A281910 A180736 A111394 * A140363 A374655 A280921

Adjacent sequences: A374857 A374858 A374859 * A374861 A374862 A374863

Keyword

nonn

Author

Clark Kimberling, Aug 18 2024

Status

approved