A338718 Define b(1)=1 and for n>1, b(n)=n/b(n-1); then a(n) = floor(b(n)).

1, 2, 1, 2, 1, 3, 2, 3, 2, 4, 2, 4, 2, 4, 3, 5, 3, 5, 3, 5, 3, 5, 3, 6, 4, 6, 4, 6, 4, 6, 4, 7, 4, 7, 4, 7, 4, 7, 5, 7, 5, 8, 5, 8, 5, 8, 5, 8, 5, 8, 5, 9, 5, 9, 5, 9, 6, 9, 6, 9, 6, 9, 6, 10, 6, 10, 6, 10, 6, 10, 6, 10, 6, 10, 6, 10, 7, 11, 7, 11, 7, 11, 7, 11, 7, 11, 7, 11, 7, 11

Offset

1,2

Links

Table of n, a(n) for n=1..90.

Example

The first few fractions b(n) are 1, 2, 3/2, 8/3, 15/8, 16/5, 35/16, 128/35, 315/128, 256/63, 693/256, 1024/231, 3003/1024, 2048/429, ...

Mathematica

a[n_] := Floor[n!!/(n - 1)!!]; Array[a, 90] (* Robert G. Wilson v, Dec 06 2020 *)

Crossrefs

Cf. A338719, A338720.

For the numerators and denominators of b(n) see A004731 and A004730.

Sequence in context: A185316 A053279 A046800 * A027350 A029327 A348844

Adjacent sequences: A338715 A338716 A338717 * A338719 A338720 A338721

Keyword

nonn

Author

N. J. A. Sloane, Nov 29 2020, following a suggestion from Anchar Koops, Nov 24 2020

Status

approved