Twice partition numbers.

Terms

a(0) =2a(1) =2a(2) =4a(3) =6a(4) =10a(5) =14a(6) =22a(7) =30a(8) =44a(9) =60a(10) =84a(11) =112a(12) =154a(13) =202a(14) =270a(15) =352a(16) =462a(17) =594a(18) =770a(19) =980a(20) =1254a(21) =1584a(22) =2004a(23) =2510a(24) =3150a(25) =3916a(26) =4872a(27) =6020a(28) =7436a(29) =9130