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 A358291 #26 Dec 27 2022 03:27:16 %S A358291 1,2,3,5,6,8,9,15,10,11,13,19,17,18,14,26,16,21,20,27,22,25,37,28,56, %T A358291 62,47,36,48,32,29,40,61,51,44,69,24,59,113,46,33,52,41,57,73,70,68, %U A358291 55,80,134,53,115,93,49,50,45,78,98,66,54,31,43,64,83,79,94,84 %N A358291 a(n) = smallest k not already in the sequence such that OEIS entry Ak contains n. %H A358291 <a href="/index/Se#selfies">Index entries for sequences whose definition involves A_n (or An)</a>. %e A358291 A000001 contains 0, so a(0) = 1. %e A358291 A000002 contains 1, so a(1) = 2. %e A358291 k = 10 is the smallest k not yet in the sequence such that Ak = A000010 contains 8, so a(8) = 10. %Y A358291 Cf. A051070, A053169, A053873. %K A358291 nonn,dumb,less %O A358291 0,2 %A A358291 _N. J. A. Sloane_, Nov 30 2022 %E A358291 More terms from _Hugo Pfoertner_, Dec 01 2022