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 A032450 #37 Jun 22 2020 07:00:33 %S A032450 1,3,2,2,3,7,6,12,4,2,3,12,4,7,6,4,7,6,12,15,8,12,28,6,12,4,7,12,4,7, %T A032450 6,28,12,6,12,4,7,8,15,8,15,31,30,72,24,60,16,6,12,4,7,24,60,16,31,30, %U A032450 72,8,15,12,28,16,31,30,72,24,60,12,28,8,15,60,16 %N A032450 Period of finite sequence g(n) related to Poulet's Conjecture. %C A032450 Poulet's Conjecture states that for any integer n, the sequence f_0(n) = n, f_2k+1(n)=sigma(f_2k(n)), f_2k(n)=phi(f_2k-1(n)) (where sigma = A000203 and phi = A000010) is eventually periodic. %D A032450 P. Poulet, Nouvelles suites arithmétiques, Sphinx vol. 2 (1932) pp. 53-54. %H A032450 Leon Alaoglu and Paul Erdős, <a href="http://dx.doi.org/10.1090/S0002-9904-1944-08257-8">A conjecture in elementary number theory</a>, Bull. Amer. Math. Soc. 50 (1944), 881-882. %H A032450 Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a032/A032450.java">Java program</a> (github) %F A032450 g(1)=n; thereafter g(2k)=sigma(g(2k-1)), g(2k+1)=phi(g(2k)). %e A032450 Poulet's sequence starting at 1 is 1->1->1->.. which contributes [1]. Starting at 2: 2->3->2->3->.. which contributes [3,2]. Starting at 3: 3->4->2->3->2->3... which contributes [2,3]. Starting at 4: 4->7->6->12->4->7->6->12.. which contributes [7, 6, 12, 4]. - _R. J. Mathar_, May 08 2020 %Y A032450 Cf. A000010, A000203, A001229, A036845, A095955, A096865. %K A032450 nonn %O A032450 1,2 %A A032450 Ursula Gagelmann (gagelmann(AT)altavista.net), Apr 07 1998 %E A032450 Revised definition and added formula from Ursula Gagelmann, Apr 07 1998 - _N. J. A. Sloane_, May 08 2020 %E A032450 Missing a(42)=31 inserted and more terms from _Sean A. Irvine_, Jun 21 2020