Number of partitions of n*(n+1)/2 with at most four parts that can be obtained from grouping (with parentheses) a permutation of the sum 1+2+...+n.

A160438

Number of partitions of n*(n+1)/2 with at most four parts that can be obtained from grouping (with parentheses) a permutation of the sum 1+2+...+n.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =5a(4) =13a(5) =35a(6) =93a(7) =215a(8) =437a(9) =815a(10) =1436a(11) =2413a(12) =3886a(13) =6041a(14) =9125a(15) =13436a(16) =19323a(17) =27221a(18) =37670a(19) =51293a(20) =68797a(21) =91025a(22) =118982a(23) =153797a(24) =196721a(25) =249206a(26) =312935a(27) =389761a(28) =481709a(29) =591080

External references