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 A143276 #6 May 29 2023 13:01:46 %S A143276 1,0,1,1,0,1,1,0,0,1,3,0,0,0,1,0,1,0,0,0,1,5,0,0,0,0,0,1,2,1,0,0,0,0, %T A143276 0,1,4,0,1,0,0,0,0,0,1,0,3,0,0,0,0,0,0,0,1,9,0,0,0,0,0,0,0,0,0,1,1,0, %U A143276 1,1,0,0,0,0,0,0,0,1,11,0,0,0,0,0,0,0,0,0,0,0,1,0,5,0,0,0,0,0,0,0,0,0,0,0,1 %N A143276 Triangle read by rows: A054525 * A054523 as infinite lower triangular matrices. %C A143276 Row sums = phi(n), A000010: (1, 1, 2, 2, 4, 2, 6,...). %C A143276 Left border = A007431: (1, 0, 1, 1, 3, 0, 5, 2, 4,...). %F A143276 Moebius transform of triangle A054523. %e A143276 First few rows of the triangle = %e A143276 1; %e A143276 0, 1; %e A143276 1, 0, 1; %e A143276 1, 0, 0, 1; %e A143276 3, 0, 0, 0, 1; %e A143276 0, 1, 0, 0, 0, 1; %e A143276 5, 0, 0, 0, 0, 0, 1; %e A143276 2, 1, 0, 0, 0, 0, 0, 1; %e A143276 ... %Y A143276 Cf. A000010, A007431, A054523, A054525. %K A143276 nonn,tabl %O A143276 1,11 %A A143276 _Gary W. Adamson_, Aug 03 2008 %E A143276 a(17), a(18) corrected by _Georg Fischer_, May 29 2023