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 A324035 #10 Feb 16 2019 19:29:59 %S A324035 2,4,5,2,4,4,3,2,3,2,0,4,0,4,0,1,2,0,1,2,0,2,4,0,2,4,0,4,5,2,0,4,5,2, %T A324035 0,5,2,4,4,0,5,2,4,4,0,4,4,5,2,3,2,0,4,4,5,2,3,2,0,5,2,3,2,4,4,0,4,0, %U A324035 3,2,3,2,4,4,0,4 %N A324035 Irregular triangle read by rows of the entries of the Collatz tree A088975 modulo 6, starting with entry 8 == 2 (mod 6). %C A324035 The length of row l of this irregular triangle is A005186(n+3), n >= 0. %C A324035 The entries of the Collatz tree A088975 modulo 6 are interesting because each 4 (mod 6) entry belongs to a vertex with outdegree 2 and all other vertices have outdegree 1. See a comment in A088975. The root 8 is chosen because the vertex 4 of the preceding level does not obey this rule (otherwise a tree repetiton would occur). %C A324035 The number of entries of level n congruent to 4 modulo 6 are given by A176866(n+4), for n >= 0. %F A324035 T(n, k) = A088975(n+3, k) (mod 6), k = 1..A005186(n+3), n >= 0. %e A324035 The irregular triangle T begins: %e A324035 n\k 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 ... A005186(n+3) %e A324035 0: 2 1 %e A324035 1: 4 1 %e A324035 2: 5 2 2 %e A324035 3: 4 4 2 %e A324035 4: 3 2 3 2 4 %e A324035 5: 0 4 0 4 4 %e A324035 6: 0 1 2 0 1 2 6 %e A324035 7: 0 2 4 0 2 4 6 %e A324035 8: 0 4 5 2 0 4 5 2 8 %e A324035 9: 0 5 2 4 4 0 5 2 4 4 10 %e A324035 10: 0 4 4 5 2 3 2 0 4 4 5 2 3 2 14 %e A324035 11: 0 5 2 3 2 4 4 0 4 0 3 2 3 2 4 4 0 4 18 %e A324035 ... %Y A324035 Cf. A005186, A088975, A176866. %K A324035 nonn,tabf,easy %O A324035 0,1 %A A324035 _Wolfdieter Lang_, Feb 14 2019