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 A290567 #16 Aug 07 2017 09:11:53 %S A290567 0,3,3,53,303,2178,5303,67803,67803,849053,6708428,6708428,6708428, %T A290567 983270928,983270928,25397333428,147467645928,605231317803, %U A290567 1368170770928,5182868036553,43329840692803,43329840692803,43329840692803,4811701422724053,52495417243036553 %N A290567 The successive approximations up to 5^n for 5-adic integer 2^(1/3). %C A290567 x = ...132203, %C A290567 x^2 = ...344214, %C A290567 x^3 = ...000002 = 2. %H A290567 Seiichi Manyama, <a href="/A290567/b290567.txt">Table of n, a(n) for n = 0..1431</a> %H A290567 Wikipedia, <a href="https://en.wikipedia.org/wiki/Hensel%27s_lemma">Hensel's Lemma</a>. %F A290567 a(0) = 0 and a(1) = 3, a(n) = a(n-1) + 2 * (a(n-1)^3 - 2) mod 5^n for n > 1. %e A290567 a(1) = ( 3)_5 = 3, %e A290567 a(2) = ( 3)_5 = 3, %e A290567 a(3) = ( 203)_5 = 53, %e A290567 a(4) = (2203)_5 = 303. %o A290567 (PARI) a(n)=truncate((2+O(5^n))^(1/3)); \\ _Joerg Arndt_, Aug 06 2017 %Y A290567 Cf. A290566, A290568. %K A290567 nonn %O A290567 0,2 %A A290567 _Seiichi Manyama_, Aug 06 2017