G.f.: Product_{k>=1} 1/(1-x^k)^(7*k).

Terms

a(0) =1a(1) =7a(2) =42a(3) =203a(4) =882a(5) =3486a(6) =12880a(7) =44885a(8) =149170a(9) =475587a(10) =1462993a(11) =4359474a(12) =12628091a(13) =35656446a(14) =98372109a(15) =265701212a(16) =703800790a(17) =1830960824a(18) =4684293222a(19) =11798774953a(20) =29288385021a(21) =71714795158a(22) =173351031721a(23) =413964243476a(24) =977243358574