a(n) = 2^n*(binomial(n,2) + 1).

Terms

a(0) =1a(1) =2a(2) =8a(3) =32a(4) =112a(5) =352a(6) =1024a(7) =2816a(8) =7424a(9) =18944a(10) =47104a(11) =114688a(12) =274432a(13) =647168a(14) =1507328a(15) =3473408a(16) =7929856a(17) =17956864a(18) =40370176a(19) =90177536a(20) =200278016a(21) =442499072a(22) =973078528a(23) =2130706432a(24) =4647288832a(25) =10099884032a(26) =21877489664a(27) =47244640256a(28) =101737037824a(29) =218506461184