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 A309453 #11 Aug 03 2019 14:19:35 %S A309453 0,3,45,339,1368,8571,42185,630430,4748145,27807349,27807349, %T A309453 1722658843,13586619301,41269193703,235047214517,2269716433064, %U A309453 30755085492722,230152668910328,928044210871949,2556457808782398,36753143364901827,196337675960125829,2430521132293261857 %N A309453 The successive approximations up to 7^n for 7-adic integer 5^(1/5). %F A309453 a(0) = 0 and a(1) = 3, a(n) = a(n-1) + (a(n-1)^5 - 5) mod 7^n for n > 1. %e A309453 a(1) = ( 3)_7 = 3, %e A309453 a(2) = ( 63)_7 = 45, %e A309453 a(3) = ( 663)_7 = 339, %e A309453 a(4) = (3663)_7 = 1368. %o A309453 (PARI) {a(n) = truncate((5+O(7^n))^(1/5))} %Y A309453 Cf. A309448. %Y A309453 Expansions of p-adic integers: %Y A309453 A290800, A290802 (7-adic, sqrt(-6)); %Y A309453 A290806, A290809 (7-adic, sqrt(-5)); %Y A309453 A290803, A290804 (7-adic, sqrt(-3)); %Y A309453 A210852, A212153 (7-adic, (1+sqrt(-3))/2); %Y A309453 A290557, A290559 (7-adic, sqrt(2)); %Y A309453 A309450 (7-adic, 2^(1/5)); %Y A309453 A309451 (7-adic, 3^(1/5)); %Y A309453 A309452 (7-adic, 4^(1/5)); %Y A309453 A309454 (7-adic, 6^(1/5)). %K A309453 nonn %O A309453 0,2 %A A309453 _Seiichi Manyama_, Aug 03 2019