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

Terms

a(0) =1a(1) =3a(2) =17a(3) =73a(4) =257a(5) =801a(6) =2305a(7) =6273a(8) =16385a(9) =41473a(10) =102401a(11) =247809a(12) =589825a(13) =1384449a(14) =3211265a(15) =7372801a(16) =16777217a(17) =37879809a(18) =84934657a(19) =189267969a(20) =419430401a(21) =924844033a(22) =2030043137a(23) =4437573633a(24) =9663676417a(25) =20971520001a(26) =45365592065a(27) =97844723713a(28) =210453397505a(29) =451508436993