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 A172049 #5 Mar 30 2012 18:52:04 %S A172049 1,1,1,3,5,7,1,3,5,7,1,3,5,7,9,11,13,15,17,1,3,5,7,9,11,13,15,17,1,3, %T A172049 5,7,9,11,13,15,17,19,21,23,25,27,29,31,1,3,5,7,9,11,13,15,17,19,21, %U A172049 23,25,27,29,31,1,3,5,7,9,11,13,15,17,19,21,23,25,27,29,31,33,35,37,39,41,43 %N A172049 Irregular triangle T(n,k) = 2k-1 with A008794(n+2) values in row n. %C A172049 These are the values A172002(2*n)-A172002(2*n-1) arranged in a table by adding line breaks. %C A172049 The last (and largest) numbers in the lines are in A056220(floor(n+1)/2). %e A172049 1; %e A172049 1; %e A172049 1, 3, 5, 7; %e A172049 1, 3, 5, 7; %e A172049 1, 3, 5, 7, 9, 11, 13, 15, 17; %e A172049 1, 3, 5, 7, 9, 11, 13, 15, 17; %e A172049 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31; %e A172049 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31; %e A172049 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43,... %Y A172049 Cf. A158405. %K A172049 nonn,easy,tabf %O A172049 1,4 %A A172049 _Paul Curtz_, Jan 24 2010