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 A249678 #17 Jan 15 2024 01:43:37 %S A249678 1,3,2,75,9,5,4,17,10,7,8,91,6,23,13,83,15,16049,43,11,16,25,26,95,12, %T A249678 449,452,99,14,451,20,453,1072,31,22,16043,34,33,56,459,24,101,18,35, %U A249678 62,37,102,19,27,39,28,21,30,109,42,41,118,117,120,487,44,45,67 %N A249678 Index of n in A125718, or 0 if n does not occur; A125718(k) = least number congruent to prime(k) (mod k) and not occurring earlier. %C A249678 If A125718 is a permutation of the positive integers, then this is the inverse permutation. %H A249678 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %o A249678 (PARI) A249678(n)=for(i=1,9e9,A125718(i)==n&&return(i)) %K A249678 nonn %O A249678 1,2 %A A249678 _M. F. Hasler_, Nov 03 2014