Number of pairs (y, v) where y is a composition of n and v is a (not necessarily contiguous) subsequence of y whose length equals the number of distinct parts in y.

A355384

Number of pairs (y, v) where y is a composition of n and v is a (not necessarily contiguous) subsequence of y whose length equals the number of distinct parts in y.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =4a(4) =12a(5) =30a(6) =66a(7) =164a(8) =419a(9) =1049a(10) =2625a(11) =6372a(12) =15451a(13) =37335a(14) =89855a(15) =216523a(16) =518714a(17) =1235897a(18) =2930050a(19) =6911149a(20) =16217817a(21) =37914515a(22) =88304358a(23) =204971388a(24) =474172899a(25) =1093547574a(26) =2513959446a(27) =5761735383a(28) =13165908506a(29) =29998936859

External references