Column 3 of triangle A123610.

Terms

a(0) =1a(1) =4a(2) =20a(3) =68a(4) =175a(5) =392a(6) =786a(7) =1440a(8) =2475a(9) =4036a(10) =6292a(11) =9464a(12) =13805a(13) =19600a(14) =27200a(15) =36996a(16) =49419a(17) =64980a(18) =84238a(19) =107800a(20) =136367a(21) =170696a(22) =211600a(23) =260000a(24) =316881a(25) =383292a(26) =460404a(27) =549460a(28) =651775a(29) =768800