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 A354201 #5 May 23 2022 17:45:40 %S A354201 1,1,2,3,7,5,13,11,19,17,23,29,37,31,43,41,47,53,59,67,61,71,79,73,89, %T A354201 97,83,103,101,109,107,127,113,131,137,139,149,151,163,157,167,173, %U A354201 179,181,193,191,199,211,223,197,229,227,233,239,241,251,257,263,269,277,271,281,283,307,293,313,311,317,331,337 %N A354201 Inverse prime map of A354200. %F A354201 For all n >= 1, a(A000720(A354200(n))) = A000040(n). %o A354201 (PARI) A354201(n) = if(n<=3,(n+1)\2,my(m=prime(n)%4); forstep(i=n-1,0,-1,if(m==(prime(i)%4),return(prime(i))))); %Y A354201 Cf. A000040, A000720, A354200, A354203. %K A354201 nonn %O A354201 1,3 %A A354201 _Antti Karttunen_, May 23 2022