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 A143110 #2 Mar 31 2012 20:25:00 %S A143110 1,1,2,1,0,1,1,2,0,2,1,0,0,0,1,1,2,1,0,0,2,1,0,0,0,0,0,1,1,2,0,2,0,0, %T A143110 0,2,1,0,1,0,0,0,0,0,1,1,2,0,0,1,0,0,0,0,2,1,0,0,0,0,0,0,0,0,0,1,1,2, %U A143110 1,2,0,2,0,0,0,0,0,2,1,0,0,0,0,0,0,0,0,0,0,0,1,1,2,0,0,0,0,1,0,0,0,0,0,0,2 %N A143110 Triangle read by rows, A051731 * A000034 * 0^(n-k), 1<=k<=n. %C A143110 Row sums = A069735: (1, 3, 2, 5, 2, 6, 2, 7,...). %C A143110 T(n,k) = 2 if k is even and divides n, 1 if k is odd and divides n; 0 otherwise. %F A143110 Triangle read by rows, A051731 * A000034 * 0^(n-k), 1<=k<=n; where A051731 = the inverse Mobius transform and A000034 = (1, 2, 1, 2, 1, 2,...). %e A143110 First few rows of the triangle are: %e A143110 1; %e A143110 1, 2; %e A143110 1, 0, 1; %e A143110 1, 2, 0, 2; %e A143110 1, 0, 0, 0, 1; %e A143110 1, 2, 1, 0, 0, 2; %e A143110 1, 0, 0, 0, 0, 0, 1; %e A143110 ... %Y A143110 Cf. A051731, A000034, A069735. %K A143110 nonn,tabl %O A143110 1,3 %A A143110 Gary W. Adamson & _Mats Granvik_, Jul 25 2008