A249615 Number of non-singleton blocks in the n-th set partition (A231428).

0, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 2, 1, 1, 1, 1, 2, 2, 2, 2, 1, 2, 2, 2, 2, 1, 2, 1, 2, 2, 2, 2, 1, 2, 1, 2, 1, 1, 2, 2, 2, 2, 1, 2, 1, 2, 1, 1, 2, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 2, 3, 2, 2, 3, 2, 2, 2, 1, 2, 2, 2, 2, 2, 3, 2, 3, 2, 2, 3, 2, 2, 2

Offset

0,7

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 2 non-singleton blocks {1,4} and {2,3}. So a(6) = 2.

Crossrefs

Cf. A231428, A249616

Sequence in context: A113310 A359537 A081653 * A096860 A128185 A175244

Adjacent sequences: A249612 A249613 A249614 * A249616 A249617 A249618

Keyword

nonn

Author

Tilman Piesk, Nov 02 2014

Status

approved