a(n) = (50*n^7 - 1197*n^6 + 11333*n^5 - 53655*n^4 + 132125*n^3 - 156828*n^2 + 73212*n + 5040)/5040.

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =6a(5) =10a(6) =15a(7) =30a(8) =171a(9) =886a(10) =3359a(11) =10143a(12) =26072a(13) =59502a(14) =123931a(15) =240048a(16) =438261a(17) =761754a(18) =1270123a(19) =2043641a(20) =3188202a(21) =4840994a(22) =7176951a(23) =10416034a(24) =14831391a(25) =20758446a(26) =28604967a(27) =38862163a(28) =52116860a(29) =69064806