Number of planar partitions of n with exactly 2 rows.

Terms

a(0) =1a(1) =2a(2) =5a(3) =9a(4) =18a(5) =30a(6) =53a(7) =85a(8) =139a(9) =215a(10) =336a(11) =504a(12) =760a(13) =1115a(14) =1635a(15) =2351a(16) =3375a(17) =4770a(18) =6725a(19) =9368a(20) =13006a(21) =17885a(22) =24510a(23) =33319a(24) =45139a(25) =60743a(26) =81457a(27) =108610a(28) =144334a(29) =190844