Sum of exponents in prime-power factorization of C(4n,2n).

Terms

a(0) =0a(1) =2a(2) =3a(3) =5a(4) =6a(5) =6a(6) =7a(7) =11a(8) =9a(9) =11a(10) =12a(11) =12a(12) =13a(13) =15a(14) =14a(15) =15a(16) =15a(17) =16a(18) =15a(19) =18a(20) =17a(21) =20a(22) =22a(23) =22a(24) =22a(25) =23a(26) =22a(27) =23a(28) =22a(29) =23