a(n) = (n+1)*(n+2)^3*(n+3)^2*(n+4)*(3n+5)/1440.

Terms

a(0) =1a(1) =24a(2) =220a(3) =1225a(4) =4998a(5) =16464a(6) =46368a(7) =115830a(8) =263175a(9) =553696a(10) =1093092a(11) =2045407a(12) =3656380a(13) =6283200a(14) =10431744a(15) =16802460a(16) =26346141a(17) =40330920a(18) =60421900a(19) =88774917a(20) =128146018a(21) =182018320a(22) =254748000a(23) =351731250a(24) =479594115a(25) =646407216a(26) =861927444