Number of partitions of n into two sorts of parts having exactly 2 parts of the second sort.

Terms

a(0) =1a(1) =4a(2) =11a(3) =24a(4) =49a(5) =89a(6) =158a(7) =262a(8) =428a(9) =667a(10) =1033a(11) =1542a(12) =2289a(13) =3313a(14) =4765a(15) =6717a(16) =9427a(17) =13011a(18) =17882a(19) =24260a(20) =32763a(21) =43775a(22) =58268a(23) =76837a(24) =100953a(25) =131629a(26) =171003a(27) =220683a(28) =283877a(29) =363016