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 A357064 #27 Aug 19 2025 09:42:35
%S A357064 1,2,3,7,418090195952691922788354
%N A357064 a(n) = k such that A091411(k) = A091409(n).
%C A357064 The existence of a(n) is proven in Lemma 1.2(a) of the article "The first occurrence of a number in Gijswijt's sequence". There, it is called t^{(1)}(n). In this article, a formula for the numbers t^{(m)}(n) is given. It looks like a tower of exponents and can be found in Theorem 6.20. This formula is then used to find a formula for the first occurrence of an integer n in Gijswijt's sequence, which is A091409(n).
%C A357064 The value of a(5) is calculated in Subsection 8.2 of the same article.
%C A357064 The value of a(6) is larger than 10^(10^100), so it would be impossible to include here.
%H A357064 Levi van de Pol, <a href="https://arxiv.org/abs/2209.04657">The first occurrence of a number in Gijswijt's sequence</a>, arXiv:2209.04657 [math.CO], 2022.
%H A357064 Levi van de Pol, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL28/Vandepol/vandepol5.html">The Growth Rate of Gijswijt's Sequence</a>, J. Int. Seq. (2025) Vol. 28, Art. No. 25.4.6. See p. 7.
%e A357064 For n=4 we have A091411(7)=A091409(4). Therefore, a(4)=7.
%Y A357064 Cf. A091409, A091411.
%K A357064 nonn
%O A357064 1,2
%A A357064 _Levi van de Pol_, Sep 10 2022