cp's OEIS Frontend

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

%I A212241 #16 May 20 2025 08:30:44
%S A212241 0,1,15,76,243,598,1249,2326,3984,6405,9786,14363,20378,28117,37864,
%T A212241 49965,64740,82591,103877,129062,158543,192832,232371,277740,329399,
%U A212241 388002,454043,528220,611087,703402,805721,918898,1043520,1180469
%N A212241 Number of 2 X 2 matrices M with terms in {1,...,n} such that permanent(M) > n.
%C A212241 a(n) + A212151(n+1) = n^4.  For a guide to related sequences, see A211795.
%t A212241 t = Compile[{{n, _Integer}}, Module[{s = 0},
%t A212241 (Do[If[w*x + y*z > n, s = s + 1],
%t A212241 {w, 1, #}, {x, 1, #}, {y, 1, #}, {z, 1, #}] &[n]; s)]];
%t A212241 Map[t[#] &, Range[0, 40]]  (* A212241 *)
%t A212241 (* _Peter J. C. Moses_, Apr 13 2012 *)
%Y A212241 Cf. A211795.
%K A212241 nonn
%O A212241 0,3
%A A212241 _Clark Kimberling_, May 08 2012