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 A007479 M2513 #20 Apr 06 2023 08:34:07 %S A007479 0,3,6,5,12,2,10,9,24,11,4,14,20,15,18,17,48,26,22,21,8,23,28,38,40, %T A007479 27,30,29,36,50,34,33,96,35,52,62,44,39,42,41,16,74,46,45,56,47,76,86, %U A007479 80,51,54,53,60,98,58,57,72,59,100,110,68,63,66,65 %N A007479 Earliest sequence with a(a(a(n))) = 2n. %D A007479 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A007479 Delbert L. Johnson, <a href="/A007479/b007479.txt">Table of n, a(n) for n = 0..19999</a> %H A007479 <a href="/index/Aa#aan">Index entries for sequences of the a(a(n)) = 2n family</a> %F A007479 a(0) = 0, a(2*n) = 2*a(n), a(6*n+1) = 6*n+3, a(6*n+3) = 6*n+5, a(6*n+5) = 12*n+2. - _Sean A. Irvine_, Jan 05 2018 %Y A007479 Cf. A002516. %K A007479 easy,nonn,nice %O A007479 0,2 %A A007479 _N. J. A. Sloane_ %E A007479 Missing a(48) = 80 inserted by _Sean A. Irvine_, Jan 05 2018