The number of 2 X 2 matrices with no real eigenvalues and whose entries are integers of absolute value at most n.

A207259

The number of 2 X 2 matrices with no real eigenvalues and whose entries are integers of absolute value at most n.

Terms

    a(0) =14a(1) =148a(2) =642a(3) =1832a(4) =4246a(5) =8420a(6) =15202a(7) =25296a(8) =39742a(9) =59668a(10) =86338a(11) =120840a(12) =165174a(13) =220356a(14) =288322a(15) =370816a(16) =470254a(17) =587940a(18) =726994a(19) =888728a(20) =1076422a(21) =1292404a(22) =1539442a(23) =1819440a(24) =2136734a(25) =2493700a(26) =2893586a(27) =3339544a(28) =3835782a(29) =4384036

External references