a(n) = binomial(n, sum_digits_n).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =1a(9) =1a(10) =10a(11) =55a(12) =220a(13) =715a(14) =2002a(15) =5005a(16) =11440a(17) =24310a(18) =48620a(19) =92378a(20) =190a(21) =1330a(22) =7315a(23) =33649a(24) =134596a(25) =480700a(26) =1562275a(27) =4686825a(28) =13123110a(29) =34597290