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 A357870 #18 Oct 19 2022 06:47:58
%S A357870 3,13,51,61,217,846,291,1001,3673,14637,1393,4683,16693,62221,247965,
%T A357870 6673,22265,77064,282317,1054081,4200768,31971,106153,360517,1285131,
%U A357870 4778353,17857153,71165091
%N A357870 Triangle of integers related to generalized Markov numbers, read by rows.
%H A357870 Esther Banaian and Archan Sen, <a href="https://arxiv.org/abs/2210.07366">A Generalization of Markov Numbers</a>, arXiv:2210.07366 [math.CO], 2022. See Table 1 p. 12 (4863 is a typo).
%e A357870 Triangle begins:
%e A357870 3;
%e A357870 13, 51;
%e A357870 61, 217, 846;
%e A357870 291, 1001, 3673, 14637;
%e A357870 1393, 4683, 16693, 62221, 247965;
%e A357870 ...
%Y A357870 Cf. A101368 (1st column).
%Y A357870 A357749 \ {1} is a subset.
%K A357870 nonn,tabl,more
%O A357870 1,1
%A A357870 _Michel Marcus_, Oct 17 2022