a(n) = sum of the exponents in the prime factorization of LCM{1, n-1, ..., C(n-[ n/2 ],[ n/2 ])}.

Terms

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