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 A143612 #6 Sep 26 2013 05:00:55 %S A143612 1,1,0,3,2,0,4,3,3,0,10,9,7,4,0,6,5,5,5,5,0,21,20,18,15,11,6,0,16,15, %T A143612 15,12,12,7,7,0,27,26,24,24,20,15,15,8,0,20,19,19,16,16,16,16,9,9,0, %U A143612 55,54,52,49,45,40,34,27,19,10,0,24,23,23,23,23,18,18,11,11,11,11,0,78,77,75 %N A143612 Triangle read by rows, A127368 * A000012, 1<=k<=n. %C A143612 Triangle read by rows, A127368 * A000012, 1<=k<=n. Triangle A127368 records the reduced residue system mod n. The operator A000012 takes partial sums starting from the right in A127368 rows. %e A143612 First few rows of the triangle = %e A143612 1; %e A143612 1, 0; %e A143612 3, 2, 0; %e A143612 4, 3, 3, 0; %e A143612 10, 9, 7, 4, 0; %e A143612 6, 5, 5, 5, 5, 0; %e A143612 21, 20, 18, 15, 11, 6, 0; %e A143612 16, 15, 15, 12, 12, 7, 7, 0; %e A143612 ... %e A143612 Row 5 = (10, 9, 7, 4, 0) since row 5 of triangle A127368 = (1, 2, 3, 4, 0). %Y A143612 Cf. A127368, A023896 (left border), A053818 (row sums). %K A143612 nonn,tabl %O A143612 1,4 %A A143612 _Gary W. Adamson_, Aug 27 2008 %E A143612 Corrected by _Jaroslav Krizek_, May 28 2010