Sum of exponents in prime-power factorization of C(4n,2n-1).

Terms

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