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 A377082 #12 Oct 16 2024 21:33:25 %S A377082 1,3,13,53,3188645 %N A377082 a(0) = 1, a(1) = 3, a(2) = 13; for n >= 2, a(n+1) = 2*3^((a(n)-1)/4) - 1. %C A377082 The next term is too large to include. %C A377082 a(n) is the least positive integer that requires n steps to reach 1 under iteration of the sum of squares of digits function in base 3 (A006287). %C A377082 a(n) is also the least positive integer that requires n steps to reach 1 under iteration of the map A375212. %H A377082 N. Bradley Fox et al., <a href="https://arxiv.org/abs/2409.09863">Elated Numbers</a>, arXiv:2409.09863 [math.NT], 2024. %H A377082 G. Lapointe, <a href="https://arxiv.org/abs/1904.12032">On finding the smallest happy numbers of any heights</a>, arXiv:1904.12032 [math.NT], 2019. %Y A377082 Cf. A006287, A007013, A375212. %K A377082 nonn %O A377082 0,2 %A A377082 N. Bradley Fox, _Nathan Fox_, Helen Grundman, Rachel Lynn, Changningphaabi Namoijam, Mary Vanderschoot, Oct 15 2024