A249616 Number of elements in non-singleton blocks in the n-th set partition (A231428).

0, 2, 2, 2, 3, 2, 4, 2, 4, 3, 2, 4, 3, 3, 4, 2, 4, 4, 4, 5, 2, 4, 4, 4, 5, 3, 5, 2, 4, 4, 4, 5, 3, 5, 3, 5, 4, 2, 4, 4, 4, 5, 3, 5, 3, 5, 4, 3, 5, 4, 4, 5, 2, 4, 4, 4, 5, 4, 6, 4, 6, 5, 4, 6, 5, 5, 6, 2, 4, 4, 4, 5, 4, 6, 4, 6, 5, 4, 6, 5, 5, 6

Offset

0,2

Links

Tilman Piesk, Table of n, a(n) for n = 0..9999

Tilman Piesk, Illustrated list of the first 52 equivalence relations

Tilman Piesk, Permutations and partitions in the OEIS (Wikiversity)

Example

The 6th set partition has the non-singleton blocks {1,4} and {2,3}, and they contain 4 elements. So a(6) = 4.

Crossrefs

Cf. A231428, A249615.

Sequence in context: A110021 A036013 A256587 * A307408 A233539 A317223

Adjacent sequences: A249613 A249614 A249615 * A249617 A249618 A249619

Keyword

nonn

Author

Tilman Piesk, Nov 02 2014

Status

approved