a(n) = Sum_{k=0..n} binomial(3*n, n-k) * q(k), where q(k) is the number of partitions into distinct parts (A000009).

A356283

a(n) = Sum_{k=0..n} binomial(3*n, n-k) * q(k), where q(k) is the number of partitions into distinct parts (A000009).

Terms

    a(0) =1a(1) =4a(2) =22a(3) =131a(4) =807a(5) =5066a(6) =32188a(7) =206242a(8) =1329733a(9) =8614685a(10) =56024538a(11) =365491218a(12) =2390613557a(13) =15671221522a(14) =102925324569a(15) =677110860689

External references