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