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 A090324 #4 Mar 31 2012 13:23:37 %S A090324 6,13,10,27,21,18,55,43,37,34,111,87,75,69,66,223,175,151,139,133,130, %T A090324 447,351,303,279,267,261,258,895,703,607,559,535,523,517,514 %N A090324 Second in a series of triangular arrays generating the natural numbers (cf. A079946). %C A090324 Note that for each triangular array T(row+1,col) = 2 * T(row,col) +1 and that the change from T(row,col+1) to T(row,col) can be readily discerned. In the first array that pattern is 1 2 4 8 ...while in the second, it becomes 3 6 12 24 48 ... and in general, the pattern for the k-th array will begin with 2k-1. %e A090324 The first array begins %e A090324 1 %e A090324 3 2 %e A090324 7 5 4 %e A090324 15 11 9 8 %e A090324 31 23 19 17 16 %e A090324 so a(1) begins with six. In general each triangular array will begin with %e A090324 the next term from A079946. %K A090324 easy,nonn,tabl %O A090324 1,1 %A A090324 _Alford Arnold_, Jan 26 2004