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 A132853 #6 Apr 03 2014 11:35:08 %S A132853 1,1,3,18,180,4347,245511,33731424,11850958449,10823718435525, %T A132853 26127739209077469,169071160476526474689,2962647736390311022542681, %U A132853 141814999458311839862777779311,18682218330844513414826192858258922 %N A132853 Number of sequences {c(i), i=0..n} that form the initial terms of a self-convolution cube of an integer sequence such that 0 < c(n) <= 3*c(n-1) for n>0 with c(0)=1. %C A132853 Equals the number of nodes at generation n in the 3-convoluted tree. The minimal path in the 3-convoluted tree is A083953 and the maximal path is A132835. The 3-convoluted tree is defined as follows: tree of all finite sequences {c(k), k=0..n} that form the initial terms of a self-convolution cube of some integer sequence such that 0 < c(n) <= 3*c(n-1) for n>0 with a(0)=1. %H A132853 Martin Fuller, <a href="/A132852/a132852.txt">Computing A132852, A132853, A132854, A132855, A132856</a> %e A132853 a(n) counts the nodes in generation n of the following tree. %e A132853 Generations 0..4 of the 3-convoluted tree are as follows; %e A132853 The path from the root is shown, with child nodes enclosed in []. %e A132853 GEN.0: [1]; %e A132853 GEN.1: 1->[3]; %e A132853 GEN.2: 1-3->[3,6,9]; %e A132853 GEN.3: %e A132853 1-3-3->[1,4,7] %e A132853 1-3-6->[1,4,7,10,13,16] %e A132853 1-3-9->[1,4,7,10,13,16,19,22,25]; %e A132853 GEN.4: %e A132853 1-3-3-1->[3] %e A132853 1-3-3-4->[3,6,9,12] %e A132853 1-3-3-7->[3,6,9,12,15,18,21] %e A132853 1-3-6-1->[3] %e A132853 1-3-6-4->[3,6,9,12] %e A132853 1-3-6-7->[3,6,9,12,15,18,21] %e A132853 1-3-6-10->[3,6,9,12,15,18,21,24,27,30] %e A132853 1-3-6-13->[3,6,9,12,15,18,21,24,27,30,33,36,39] %e A132853 1-3-6-16->[3,6,9,12,15,18,21,24,27,30,33,36,39,42,45,48] %e A132853 1-3-9-1->[3] %e A132853 1-3-9-4->[3,6,9,12] %e A132853 1-3-9-7->[3,6,9,12,15,18,21] %e A132853 1-3-9-10->[3,6,9,12,15,18,21,24,27,30] %e A132853 1-3-9-13->[3,6,9,12,15,18,21,24,27,30,33,36,39] %e A132853 1-3-9-16->[3,6,9,12,15,18,21,24,27,30,33,36,39,42,45,48] %e A132853 1-3-9-19->[3,6,9,12,15,18,21,24,27,30,33,36,39,42,45,48,51,54,57] %e A132853 1-3-9-22->[3,6,9,12,15,18,21,24,27,30,33,36,39,42,45,48,51,54,57,60,63,66 ] %e A132853 1-3-9-25->[3,6,9,12,15,18,21,24,27,30,33,36,39,42,45,48,51,54,57,60,63,66,69,72,75]. %e A132853 Each path in the tree from the root node forms the initial terms of %e A132853 a self-convolution cube of a sequence of integer terms. %Y A132853 Cf. A132852, A132854, A132855, A132856. %Y A132853 Cf. A083953, A132835. %K A132853 nonn %O A132853 0,3 %A A132853 _Paul D. Hanna_, Sep 19 2007, Oct 06 2007 %E A132853 Extended by _Martin Fuller_, Sep 24 2007.