Number of set partitions of [n] having exactly two pairs (m,m+1) such that m+1 is in some block b and m is in block b+1.
A270956
Number of set partitions of [n] having exactly two pairs (m,m+1) such that m+1 is in some block b and m is in block b+1.
Terms
- a(0) =3a(1) =27a(2) =159a(3) =857a(4) =4726a(5) =27385a(6) =167097a(7) =1071422a(8) =7203162a(9) =50674005a(10) =372321574a(11) =2851766861a(12) =22729523020a(13) =188191920799
External references
- oeis: A270956