Sum of exponents in prime-power factorization of C(3n,n+1).

Terms

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