Sum of exponents in prime-power factorization of C(3n,n-2).

Terms

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