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 A123328 #5 Sep 20 2012 04:55:38
%S A123328 1,3,5,9,11,19,18,33,28,48,41,70,50,96,69,118,87,152
%N A123328 Let M be the matrix defined in A111490. Sequence gives M(1,1), M(1,2)+M(1,2)+M(2,2), M(1,3)+M(2,3)+M(3,1)+M(3,2)+M(3,3), etc.
%F A123328 a(n)= Sum_{j=1..n} |[Sum_{i=1..j} M(i,j) + Sum_{i=1..j} M(j,i) - M(j,j)](-1)^j| Let b(n) be the numbers of the sequence A123326: a(n)= b(n)+2*[(-1)^(n+1)]*Sum_{i=n-1..1} b(i) for n even a(n)= b(n)+2*[(-1)^n]*Sum_{i=n-1..1} b(i) for n odd
%e A123328 a(4)= 1+2+3+4+1+2+1 - (1+2+3+1+1) + (1+2+1) - 1 = 9
%Y A123328 Cf. A111490, A123326.
%K A123328 easy,nonn
%O A123328 0,2
%A A123328 _Paolo P. Lava_ and _Giorgio Balzarotti_, Sep 26 2006