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 A357986 #11 Oct 23 2022 13:42:55 %S A357986 1,2,4,5,3,7,8,6,12,14,11,9,10,16,13,20,19,15,25,18,17,21,27,26,22,29, %T A357986 23,24,28,31,32,30,36,34,33,38,35,43,41,44,37,46,40,39,49,51,42,48,45, %U A357986 50,47,55,57,54,52,53,63,58,56,67,60,59,62,65,61,69,66 %N A357986 a(n) is the unique k such that A357579(k) = A007916(n), or -1 if no such k exists. %H A357986 Rémy Sigrist, <a href="/A357986/b357986.txt">Table of n, a(n) for n = 1..10000</a> %H A357986 Rémy Sigrist, <a href="/A357986/a357986.gp.txt">PARI program</a> %e A357986 A357579(36) = 42 = A007916(33), so a(33) = 36. %o A357986 (PARI) See Links section. %Y A357986 Cf. A007916, A357579. %K A357986 nonn %O A357986 1,2 %A A357986 _Rémy Sigrist_, Oct 23 2022