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 A228821 #25 Sep 18 2013 12:31:55 %S A228821 0,-1,1,-2,-1,0,3,-3,-2,-2,-1,-1,0,2,7,-4,-3,-3,-3,-2,-2,-2,-2,-1,-1, %T A228821 -1,0,1,2,6,15,-5,-4,-4,-4,-4,-3,-3,-3,-3,-3,-3,-3,-2,-2,-2,-2,-2,-2, %U A228821 -2,-1,-1,-1,-1,0,0,1,1,2,5,6,14,31,-6,-5,-5,-5,-5 %N A228821 Triangle read by rows in which row n lists the F-ranks of all compositions of n in nondecreasing order, n >= 0. %C A228821 Also row n lists the L-ranks of all compositions of n in nondecreasing order. For the definition of both F-rank and L-rank of a composition see A228820. %C A228821 Row sums is always 0. %C A228821 Row lengths is A000079. %C A228821 Column 1 is -1*A001477(n). %C A228821 Right border gives A000225. %C A228821 Row sums of nonnegative terms give A228820. %e A228821 Triangle begins: %e A228821 0; %e A228821 -1, 1; %e A228821 -2, -1, 0, 3; %e A228821 -3, -2, -2, -1, -1, 0, 2, 7; %e A228821 -4, -3, -3, -3, -2, -2, -2, -2, -1, -1, -1, 0, 1, 2, 6, 15; %e A228821 -5, -4, -4, -4, -4, -3, -3, -3, -3, -3, -3, -3, -2, -2, -2, -2, -2, -2, -2, -1, -1, -1, -1, 0, 0, 1, 1, 2, 5, 6, 14, 31; %Y A228821 Cf. A000079, A000225, A001477, A011782, A001511, A001792, A195012, A209616, A228369, A228525, A228820. %K A228821 sign,tabf %O A228821 1,4 %A A228821 _Omar E. Pol_, Sep 05 2013