Sum of exponents of primes in multinomial coefficient M(3n; n+1,n,n-1).

Terms

a(0) =1a(1) =4a(2) =6a(3) =8a(4) =8a(5) =12a(6) =12a(7) =13a(8) =13a(9) =15a(10) =17a(11) =20a(12) =19a(13) =22a(14) =21a(15) =22a(16) =21a(17) =24a(18) =25a(19) =26a(20) =25a(21) =31a(22) =30a(23) =32a(24) =30a(25) =31a(26) =33a(27) =33a(28) =32a(29) =36