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 A332440 #20 Jun 19 2020 04:42:19 %S A332440 0,10,14,1,5,33,24,34,38,15,25,29,6,16,20,7,11,39,2,30,40,21,31,35,12, %T A332440 22,26,3,13,17,4,8,36,27,37,41,18,28,32,9,19,23 %N A332440 Three-column array read by rows: the sequence of 14 triples of the positions of the numbers 0 to 13 in sequence A332439. %C A332440 A332439 gives the vertex labels of a directed Euler tour (directed Eulerian cycle) on the regular 14-gon. Every label k from {0,1, ..., 13} for the vertices V^{(14)}_k (nodes) of this regular digraph of degree 6 appears thrice in this Euler tour of length 42. %C A332440 The three positions of k in the tour A332439 = T are T(a(3*k)), T(a(3*k+1)) and T(a(3*k+2)), for k from {0,1, ..., 13}. %F A332440 T(n, k), for n = 0, 1, ..., 13 and k = 1, 2, and 3, is the first, second and third appearance of n in A332439. %e A332440 The label 0 (vertex V^{14}_0 = (r, 0) in Cartesian coordinates) appears at positions 0, 10 and 14 in the Euler tour A332439. This means that starting at V^{14}_0, one reaches this vertex again after 10 steps (a closed directed trail, using only distinct arrows). But no periodicity has been reached yet, and after another four steps one visits V^{14}_0 again (position 14), and finally periodicity is reached after another 28 steps (position 42 == 0 (mod 14)). %e A332440 The array T(n, k) in full is: %e A332440 n\k 1 2 3 %e A332440 -------------- %e A332440 0: 0 10 14 %e A332440 1: 1 5 33 %e A332440 2: 24 34 38 %e A332440 3: 15 25 29 %e A332440 4: 6 16 20 %e A332440 5: 7 11 39 %e A332440 6: 2 30 40 %e A332440 7: 21 31 35 %e A332440 8: 12 22 26 %e A332440 9: 3 13 17 %e A332440 10: 4 8 36 %e A332440 11: 27 37 41 %e A332440 12: 18 28 32 %e A332440 13: 9 19 23 %Y A332440 Cf. A332439. %K A332440 nonn,tabf,fini,full,easy,less %O A332440 0,2 %A A332440 _Wolfdieter Lang_, Apr 04 2020