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 A195838 #14 Mar 30 2012 17:34:07 %S A195838 1,1,1,1,1,1,2,1,3,1,4,1,-1,4,1,-1,4,2,-1,5,3,-1,7,4,-1,10,4,-2,12,4, %T A195838 -3,13,5,-4,14,7,-4,-1,16,10,-4,-1,21,12,-5,-1,27,13,-7,-1,32,14,-10, %U A195838 -1,35,16,-12,-2,1,38,21,-13,-3,1,44,32,-14,-4,1 %N A195838 Triangle read by rows which arises from A195828, in the same way as A175003 arises from A195310. Column k starts at row A001082(k+1). %C A195838 The sum of terms of row n is equal to the leftmost term of row n+1. This sequence is related to the generalized octagonal numbers A001082, A195828 and A195848 in the same way as A175003 is related to the generalized pentagonal numbers A001318, A195310 and A000041. See comments in A195825. %e A195838 Written as a triangle: %e A195838 . 1; %e A195838 . 1; %e A195838 . 1; %e A195838 . 1; %e A195838 . 1, 1; %e A195838 . 2, 1; %e A195838 . 3, 1; %e A195838 . 4, 1, -1; %e A195838 . 4, 1, -1; %e A195838 . 4, 2, -1; %e A195838 . 5, 3, -1; %e A195838 . 7, 4, -1; %e A195838 . 10, 4, -2; %e A195838 . 12, 4, -3; %e A195838 . 13, 5, -4; %e A195838 . 14, 7, -4, -1; %e A195838 . 16, 10, -4, -1; %e A195838 . 21, 12, -5, -1; %e A195838 . 27, 13, -7, -1; %e A195838 . 32, 14, -10, -1; %e A195838 . 35, 16, -12, -2, 1; %e A195838 . 38, 21, -13, -3, 1; %Y A195838 Row sums give A195848. %Y A195838 Cf. A001082, A175003, A195828, A195836, A195837. %K A195838 sign,tabf %O A195838 1,7 %A A195838 _Omar E. Pol_, Sep 24 2011