A338735 a(n) = Bell(n) + n - 2 (cf. A000110).

0, 2, 6, 17, 55, 207, 882, 4146, 21154, 115983, 678579, 4213607, 27644448, 190899334, 1382958558, 10480142161, 82864869819, 682076806175, 5832742205074, 51724158235390, 474869816156770, 4506715738447343, 44152005855084367, 445958869294805311, 4638590332229999376

Offset

1,2

References

Colin Defant, Highly sorted permutations and Bell numbers, ECA 1:1 (2021) Article S2R6.

Links

Table of n, a(n) for n=1..25.

Colin Defant, Highly Sorted Permutations and Bell Numbers, arXiv:2012.03869 [math.CO], 2020.

Formula

E.g.f.: exp(exp(x) - 1) + exp(x) * (x - 2) + 1. - Ilya Gutkovskiy, Dec 08 2020

Crossrefs

Cf. A000110.

Sequence in context: A148453 A097514 A108630 * A161408 A150033 A150034

Adjacent sequences: A338732 A338733 A338734 * A338736 A338737 A338738

Keyword

nonn

Author

N. J. A. Sloane, Dec 07 2020

Status

approved