A144646 a(n) = Bell(n) - 2^n + n.

0, 0, 0, 0, 3, 25, 145, 756, 3892, 20644, 114961, 676533, 4209513, 27636258, 190882952, 1382925792, 10480076627, 82864738749, 682076544033, 5832741680788, 51724157186816, 474869814059620, 4506715734253041, 44152005846695761, 445958869278028097

Offset

0,5

Comments

Number of partitions of an n-set having more than one block of size > 1. - Peter Luschny, Apr 10 2011

Links

Amiram Eldar, Table of n, a(n) for n = 0..576

Example

a(5) = 25 = card({25|134, 35|124, 125|34, 345|12, 45|123, 235|14, 15|234, 145|23, 135|24, 245|13, 25|4|13, 35|4|12, 45|3|12, 5|24|13, 5|12|34, 1|35|24, 35|2|14, 25|3|14, 5|14|23, 1|45|23, 15|4|23, 45|2|13, 15|3|24, 15|2|34, 1|25|34}). - Peter Luschny, Apr 10 2011

Mathematica

Table[BellB[n] - 2^n + n, {n, 0, 24}] (* Amiram Eldar, Nov 23 2019 *)

Prog

(Magma) [Bell(n) -2^n +n: n in [0..30]]; // G. C. Greubel, Oct 12 2023
(SageMath) [bell_number(n) - 2^n +n for n in range(31)] # G. C. Greubel, Oct 12 2023

Crossrefs

Cf. A000110, A094782.

Sequence in context: A112495 A034578 A265874 * A308417 A277520 A367507

Adjacent sequences: A144643 A144644 A144645 * A144647 A144648 A144649

Keyword

nonn

Author

Jean-Yves Tallet and N. J. A. Sloane, Jan 26 2009

Status

approved