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 A232558 #17 Jul 23 2025 07:29:27 %S A232558 5,7,11,13,17,19,31,47,59,61,83,97,109,131,137,139,173,193,211,233, %T A232558 239,241,257,271,277,281,283,307,389,397,409,431,433,457,467,491,523, %U A232558 563,569,571,653,661,673,701,709,733,821,823,859,887,911,967,983,991 %N A232558 a(1)=5, q=a(n) is the smallest prime > a(n-1) such that q-2*n = p prime. %C A232558 Conjecture: the sequence is infinite. %C A232558 Remarks: the primes p appears in increasing order but with repetition, all the primes are not present in p,q. %H A232558 Pierre CAMI, <a href="/A232558/b232558.txt">Table of n, a(n) for n = 1..10000</a> %e A232558 5-3=2 a(1)=5 %e A232558 7-3=4 a(2)=7 %e A232558 11-5=6 a(3)=11 %e A232558 13-5=8 a(4)=13 %e A232558 17-7=10 a(5)=17 %t A232558 a[1]=5;a[n_]:=a[n]=(For[k=a[n-1]+2,!(k>2n&&PrimeQ[k]&&PrimeQ[k-2n]),k++];k) %Y A232558 Cf. A020483 %K A232558 nonn %O A232558 1,1 %A A232558 _Pierre CAMI_, Nov 26 2013