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 A195839 #12 Mar 30 2012 17:34:09 %S A195839 1,1,1,1,1,1,1,2,1,3,1,4,1,-1,4,1,-1,4,1,-1,4,2,-1,5,3,-1,7,4,-1,10,4, %T A195839 -2,12,4,-3,13,4,-4,13,5,-4,14,7,-4,-1,16,10,-4,-1,21,12,-5,-1,27,13, %U A195839 -7,-1,32,13,-10,-1,34,14,-12,-1,36,16,-13,-2,1 %N A195839 Triangle read by rows which arises from A195829, in the same way as A175003 arises from A195310. Column k starts at row A118277(k). %C A195839 The sum of terms of row n is equal to the leftmost term of row n+1. This sequence is related to the generalized enneagonal numbers A118277, A195829 and A195849 in the same way as A175003 is related to the generalized pentagonal numbers A001318, A195310 and A000041. See comments in A195825. %e A195839 Written as a triangle: %e A195839 . 1; %e A195839 . 1; %e A195839 . 1; %e A195839 . 1; %e A195839 . 1; %e A195839 . 1, 1; %e A195839 . 2, 1; %e A195839 . 3, 1; %e A195839 . 4, 1, -1; %e A195839 . 4, 1, -1; %e A195839 . 4, 1, -1; %e A195839 . 4, 2, -1; %e A195839 . 5, 3, -1; %e A195839 . 7, 4, -1; %e A195839 . 10, 4, -2; %e A195839 . 12, 4, -3; %e A195839 . 13, 4, -4; %e A195839 . 13, 5, -4; %e A195839 . 14, 7, -4, -1; %e A195839 . 16, 10, -4, -1; %e A195839 . 21, 12, -5, -1; %Y A195839 Row sums give A195849. %Y A195839 Cf. A001082, A175003, A195828, A195836, A195837, A195838. %K A195839 sign,tabf %O A195839 1,8 %A A195839 _Omar E. Pol_, Sep 24 2011