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 A265406 #13 Apr 15 2019 06:06:51 %S A265406 1,2,3,4,5,6,8,10,19,14,28,13,31,20,11,7,9,15,17,16,35,48,69,42,87,50, %T A265406 71,52,97,38,101,12,25,21,82,44,54,89,99,23,56,58,140,142,63,144,146, %U A265406 22,84,24,40,149,103,75,121,65 %N A265406 a(n) = index of n in A265405 and 0 if n is not present in that sequence. %o A265406 (Scheme, with code for A265405 defined with defineperm1-macro also required) %o A265406 (define (A265406 n) (A265405 (- n))) ;; This returns inverse values of A265405 from its hidden cache. %Y A265406 Cf. A265405. %K A265406 nonn,more %O A265406 1,2 %A A265406 _Antti Karttunen_, Dec 29 2015 %E A265406 a(47)-a(56) from _Rémy Sigrist_, Feb 15 2019