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 A247895 #22 Apr 22 2020 06:54:44
%S A247895 3,7,13,31,69,190,444,1052,2702,6455,15928,40073,100370,251707,637321,
%T A247895 1617175,4124448,10553415,27066978,69709680,179992909,465769803,
%U A247895 1208198532,3140421716,8179002120,21338685408,55762149030,145935689361,382465573486,1003652347100
%N A247895 Least integer k > 0 such that prime(k) - k*n is prime.
%C A247895 Conjecture: (i) a(n) exists for any n > 0.
%C A247895 (ii) For each integer n > 2, there is a positive integer k with k*n - prime(k) prime.
%H A247895 Giovanni Resta, <a href="/A247895/b247895.txt">Table of n, a(n) for n = 1..50</a>
%H A247895 Zhi-Wei Sun, <a href="http://arxiv.org/abs/1409.5685">A new theorem on the prime-counting function</a>, arXiv:1409.5685 [math.NT], 2014-2017.
%e A247895 a(1) = 3 since prime(3) - 3*1 = 5 - 3 = 2 is prime.
%t A247895 Do[k=1; Label[aa]; If[Prime[k]>k*n&&PrimeQ[Prime[k]-k*n],Print[n," ",k]; Goto[bb]]; k=k+1; Goto[aa]; Label[bb]; Continue,{n,1,22}]
%Y A247895 Cf. A000040, A247278, A247793.
%K A247895 nonn
%O A247895 1,1
%A A247895 _Zhi-Wei Sun_, Sep 28 2014
%E A247895 Terms a(23) and beyond from _Giovanni Resta_, Apr 22 2020