a(n) = (A372966(n) - 1)/240.

Terms

a(0) =0a(1) =1a(2) =27a(3) =257a(4) =1625a(5) =6508a(6) =24010a(7) =65793a(8) =177174a(9) =391626a(10) =893101a(11) =1665644a(12) =3398759a(13) =5786411a(14) =10531652a(15) =16843009a(16) =29065308a(17) =42698935a(18) =70764303a(19) =100231882a(20) =155608837a(21) =215237342a(22) =326294606a(23) =426404460a(24) =634767250a(25) =819100920a(26) =1162438641a(27) =1480961067a(28) =2084357107a(29) =2538128133