Number of set partitions of [n] into m blocks such that for each pair of distinct cyclically consecutive blocks (b,c) = (b,(b mod m)+1) at least one pair of numbers (i,j) = (i,(i mod n)+1) exists with i member of b and j member of c.
A271272
Number of set partitions of [n] into m blocks such that for each pair of distinct cyclically consecutive blocks (b,c) = (b,(b mod m)+1) at least one pair of numbers (i,j) = (i,(i mod n)+1) exists with i member of b and j member of c.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =5a(4) =13a(5) =36a(6) =110a(7) =374a(8) =1404a(9) =5750a(10) =25419a(11) =120325a(12) =606210a(13) =3234618a(14) =18202851a(15) =107647893a(16) =666903189a(17) =4316424771a(18) =29116689197a(19) =204259773724
External references
- oeis: A271272