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

Terms

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