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 A159936 #16 Jul 31 2019 03:53:44 %S A159936 1,1,1,1,1,2,1,1,2,2,1,1,2,3,4,1,1,2,2,3,2,1,1,2,3,4,5,6,1,1,2,2,4,4, %T A159936 4,4,1,1,2,3,3,3,6,6,6,1,1,2,2,4,4,5,4,5,4,1,1,2,3,4,5,6,7,8,9,10,1,1, %U A159936 2,2,3,2,4,4,6,6,4,4,1,1,2,3,4,5,6,7,8,9,10,11,12,1,1,2,2,4,4,6,6,7,6,7,6,7,6 %N A159936 Triangle read by rows, A051731 * A054533 * transpose(A101688), provided A101688 is read as a square array. %C A159936 Row sums = A057661: (1, 2, 4, 6, 11, 11, 22,...). Right border = A000010, phi(n). %F A159936 Triangle read by rows, A051731 * A054533 * A000012. A051731 = the inverse Mobius transform. A054533 = the lower left half of the Ramanujan sum table. The operation (* transpose(A101688)) takes partial sums of (A051731 * A054533) starting from the right. [Edited by _Petros Hadjicostas_, Jul 30 2019] %e A159936 First few rows of the triangle are as follows: %e A159936 1; %e A159936 1, 1; %e A159936 1, 1, 2; %e A159936 1, 1, 2, 2; %e A159936 1, 1, 2, 3, 4; %e A159936 1, 1, 2, 2, 3, 2; %e A159936 1, 1, 2, 3, 4, 5, 6; %e A159936 1, 1, 2, 2, 4, 4, 4, 4; %e A159936 1, 1, 2, 3, 3, 3, 6, 6, 6; %e A159936 1, 1, 2, 2, 4, 4, 5, 4, 5, 4; %e A159936 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10; %e A159936 1, 1, 2, 2, 3, 2, 4, 4, 6, 6, 4, 4; %e A159936 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12; %e A159936 1, 1, 2, 2, 4, 4, 6, 6, 7, 6, 7, 6, 7, 6; %e A159936 1, 1, 2, 3, 3, 3, 5, 4, 3, 5, 9, 8, 10, 9, 8; %e A159936 1, 1, 2, 2, 4, 4, 4, 4, 8, 8, 8, 8, 8, 8, 8, 8; %e A159936 ... %Y A159936 Cf. A000010, A051731, A054532, A054533, A054534, A054535, A057661, A101688. %K A159936 nonn,tabl %O A159936 1,6 %A A159936 _Gary W. Adamson_, Apr 26 2009 %E A159936 Name edited by _Petros Hadjicostas_, Jul 30 2019