This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A085340 #8 Oct 15 2013 22:32:13
%S A085340 -1,1,4,41,528,8177,148160,3077713,72147712,1884629825,54294967296,
%T A085340 1710428956601,58496602689536,2158563109641265,85487558566199296,
%U A085340 3616912482448035233,162819625954342010880,7770488166051562690817,391896604540625999888384
%N A085340 a(n) is the value of determinant of the following special matrix: diagonal values equal to n-2; upper triangular entries equal to -1; lower triangular values are +1.
%C A085340 These invertible matrices are used in formal neural network theory to generate transient-free state transition graphs with using suitable threshold vectors.
%D A085340 Labos E.: The most complicated networks of formal neurons. In Proc. of IEEE. first International Conference on Neural Networks. San Diego,USA,1987.[Editors: Caudill,M. and Butler Ch.]; Vol. III, pp. 301-308.
%e A085340 n=5: matrix =
%e A085340 +3,-1,-1,-1,-1
%e A085340 +1,+3,-1,-1,-1
%e A085340 +1,+1,+3,-1,-1
%e A085340 +1,+1,+1,+3,-1
%e A085340 +1,+1,+1,+1,+3,
%e A085340 with determinant=528=a(5). a(1)=-1 is the only negative term.
%t A085340 f[x_, y_] := Sign[y-x] g[x_, y_, z_] := (z-2)*(1-Abs[f[x, y]]); a=Table[Table[f[w, s], {w, 1, q}], {s, 1, q}]; b=Table[Table[g[w, s, q], {w, 1, q}], {s, 1, q}]; m=matrix=a+b; Det[m]; Table[Det[Table[Table[f[w, s]+g[w, s, q], {w, 1, q}], {s, 1, q}]], {q, 1, 20}]
%K A085340 sign
%O A085340 1,3
%A A085340 _Labos Elemer_, Jul 08 2003