Number of 2 X 2 matrices having all terms in {1,...,n} and determinant in the closed interval [0,n].

A211057

Number of 2 X 2 matrices having all terms in {1,...,n} and determinant in the closed interval [0,n].

Terms

    a(0) =1a(1) =10a(2) =36a(3) =91a(4) =179a(5) =330a(6) =516a(7) =802a(8) =1150a(9) =1615a(10) =2119a(11) =2873a(12) =3595a(13) =4558a(14) =5653a(15) =6967a(16) =8245a(17) =10020a(18) =11642a(19) =13846a(20) =16053a(21) =18524a(22) =20944a(23) =24393a(24) =27405a(25) =30924a(26) =34637a(27) =39035a(28) =42961a(29) =48396

External references