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 A128258 #2 Mar 30 2012 17:25:19 %S A128258 1,0,1,-1,2,1,-1,-1,3,1,-1,0,0,4,1,0,-3,-1,0,5,1,-1,0,0,0,0,6,1,0,0, %T A128258 -3,-1,0,0,7,1,0,-2,-1,0,0,0,0,8,1,0,-1,0,-4,-1,0,0,0,9,1 %N A128258 Moebius transform of A128229. %C A128258 Row sums = phi(n), A000010: (1, 1, 2, 2, 4, 2, 6,...). A128259 = inverse Moebius transform of A128229. %F A128258 A054525 * A128229 %e A128258 First few rows of the triangle are: %e A128258 1; %e A128258 0, 1; %e A128258 -1, 2, 1; %e A128258 -1, -1, 3, 1; %e A128258 -1, 0, 0, 4, 1; %e A128258 0, -3, -1, 0, 5, 1; %e A128258 ... %Y A128258 Cf. A128259, A128229, A054525, A000010. %K A128258 tabl,sign %O A128258 1,5 %A A128258 _Gary W. Adamson_, Feb 21 2007