Number of n-element subsets of [n+10] having an even sum.

Terms

a(0) =1a(1) =5a(2) =30a(3) =146a(4) =511a(5) =1491a(6) =3976a(7) =9752a(8) =21942a(9) =46126a(10) =92252a(11) =176484a(12) =323554a(13) =571802a(14) =980232a(15) =1634776a(16) =2656511a(17) =4217499a(18) =6560554a(19) =10016006a(20) =15024009a(21) =22174581a(22) =32253936a(23) =46282704a(24) =65567164a(25) =91786604a(26) =127089144a(27) =174169352a(28) =236372692a(29) =317866884