a(n) = Sum_{j=0..n} (n+j)*binomial(n+j,j).

Terms

a(0) =0a(1) =5a(2) =35a(3) =189a(4) =924a(5) =4290a(6) =19305a(7) =85085a(8) =369512a(9) =1587222a(10) =6760390a(11) =28601650a(12) =120349800a(13) =504131940a(14) =2103781365a(15) =8751023325a(16) =36300541200a(17) =150217371150a(18) =620309379690