a(n) = (n+1)*binomial(n+7, 7).

Terms

a(0) =1a(1) =16a(2) =108a(3) =480a(4) =1650a(5) =4752a(6) =12012a(7) =27456a(8) =57915a(9) =114400a(10) =213928a(11) =381888a(12) =655044a(13) =1085280a(14) =1744200a(15) =2728704a(16) =4167669a(17) =6229872a(18) =9133300a(19) =13156000a(20) =18648630a(21) =26048880a(22) =35897940a(23) =48859200a(24) =65739375a(25) =87512256a(26) =115345296a(27) =150629248a(28) =195011080a(29) =250430400