Binomial(prime(n),s)/prime(n) where s is the sum of the decimal digits of n.

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =42a(5) =132a(6) =1144a(7) =3978a(8) =35530a(9) =1a(10) =15a(11) =210a(12) =2470a(13) =22386a(14) =228459a(15) =2908360a(16) =37584261a(17) =284291205a(18) =3701413144a(19) =35a(20) =852a(21) =19019a(22) =349812a(23) =6529292a(24) =132435472a(25) =2000945100a(26) =24366118700a(27) =328386663605a(29) =2072a(30) =81375