Number of partitions of n*(n+1).

Terms

a(0) =1a(1) =2a(2) =11a(3) =77a(4) =627a(5) =5604a(6) =53174a(7) =526823a(8) =5392783a(9) =56634173a(10) =607163746a(11) =6620830889a(12) =73232243759a(13) =819876908323