A212241 Number of 2 X 2 matrices M with terms in {1,...,n} such that permanent(M) > n.

0, 1, 15, 76, 243, 598, 1249, 2326, 3984, 6405, 9786, 14363, 20378, 28117, 37864, 49965, 64740, 82591, 103877, 129062, 158543, 192832, 232371, 277740, 329399, 388002, 454043, 528220, 611087, 703402, 805721, 918898, 1043520, 1180469

Offset: 0

Author

Clark Kimberling, May 08 2012

Keywords

• nonn

Comments

a(n) + A212151(n+1) = n^4. For a guide to related sequences, see A211795.

Crossrefs

Cf. A211795.

Programs

Mathematica

t = Compile[{{n, _Integer}}, Module[{s = 0},
(Do[If[w*x + y*z > n, s = s + 1],
{w, 1, #}, {x, 1, #}, {y, 1, #}, {z, 1, #}] &[n]; s)]];
Map[t[#] &, Range[0, 40]]  (* A212241 *)
(* Peter J. C. Moses, Apr 13 2012 *)