Number of 2 X 2 non-singular integer matrices with entries from {0,...,n}.

Terms

a(0) =0a(1) =6a(2) =50a(3) =192a(4) =512a(5) =1126a(6) =2146a(7) =3760a(8) =6112a(9) =9430a(10) =13922a(11) =19888a(12) =27504a(13) =37206a(14) =49202a(15) =63872a(16) =81600a(17) =102854a(18) =127874a(19) =157328a(20) =191440a(21) =230870a(22) =276114a(23) =327776a(24) =386128a(25) =452118a(26) =526178a(27) =608960a(28) =701056a(29) =803430