A275075 Number of set partitions of [n] such that i-j is a multiple of eight for all i,j belonging to the same block.
1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 4, 8, 16, 32, 64, 128, 256, 640, 1600, 4000, 10000, 25000, 62500, 156250, 390625, 1171875, 3515625, 10546875, 31640625, 94921875, 284765625, 854296875, 2562890625, 8884687500, 30800250000, 106774200000, 370150560000, 1283188608000
Offset: 0
Keywords
Examples
a(9) = 2: 19|2|3|4|5|6|7|8, 1|2|3|4|5|6|7|8|9.
Links
- Alois P. Heinz, Table of n, a(n) for n = 0..850
- Wikipedia, Partition of a set
Formula
a(n) = Product_{i=0..7} A000110(floor((n+i)/8)).