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 A359705 #13 Jan 14 2023 09:39:49
%S A359705 1,4,28,232,2092,19864,195352,1970896,20275692,211825600,2240855128,
%T A359705 23952786400,258287602744,2806152315048,30686462795856,
%U A359705 337490492639512,3730522624066540,41422293291178872,461802091590831904,5167329622166765872
%N A359705 Cogrowth sequence of the Brin-Navas group B.
%C A359705 This is the number of words of length 2n equal to the identity in the letters t, t^{-1}, a, a^{-1} which generate the Brin-Navas group B.
%H A359705 Andrew Elvey Price, <a href="/A359705/b359705.txt">Table of n, a(n) for n = 0..126</a>
%H A359705 Andrew Elvey Price and A. J. Guttmann, <a href="http://arxiv.org/abs/1706.07571">Numerical studies of Thompson's group F and related groups</a>, arXiv:1706.07571 [math.GR], 2017.
%e A359705 For n=1 there are 4 words of length 2 equal to the identity: aa^{-1}, a^{-1}a, tt^{-1}, t^{-1}t.
%K A359705 nonn,walk
%O A359705 0,2
%A A359705 _Andrew Elvey Price_, Jan 11 2023