Number of planar partitions of n with exactly 4 rows.

Terms

a(0) =1a(1) =2a(2) =5a(3) =11a(4) =24a(5) =46a(6) =90a(7) =164a(8) =298a(9) =520a(10) =899a(11) =1512a(12) =2521a(13) =4116a(14) =6659a(15) =10609a(16) =16753a(17) =26126a(18) =40419a(19) =61889a(20) =94067a(21) =141736a(22) =212123a(23) =315087a(24) =465162a(25) =682188a(26) =994857a(27) =1442340a(28) =2080332a(29) =2984724