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 A141045 #3 Mar 30 2012 18:51:58 %S A141045 -1,1,-1,-19,11,-19,27,-11,11,-27,-863,271,-191,271,-863,1375,-351, %T A141045 191,-191,351,-1375,-33953,7297,-3233,2497,-3233,7297,-33953 %N A141045 Triangle of subsequences of A140825 with a mirror symmetry. %C A141045 The triangle shows A140825(3) in the first row and fills the n-th row by successively skipping two terms of A140825 and taking the next n terms. The absolute values of the triangle generated this way are symmetric with respect to mirror-operation at the row centers. We are essentially reading numerators down columns of the triangle in A140825, a(i,j), 0<=i<=j-2. %e A141045 The triangle starts: %e A141045 -1; %e A141045 1, -1; %e A141045 -19, 11, -19; %e A141045 27, -11, 11, -27; %K A141045 sign,tabl,less %O A141045 0,4 %A A141045 _Paul Curtz_, Jul 31 2008 %E A141045 Edited by _R. J. Mathar_, Aug 12 2008