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 A064271 #17 Jun 25 2023 18:52:10
%S A064271 18,20,36,100,104,196,324,392,464,576,650,784,800,900,968,1352,1936,
%T A064271 1952,2450,2500,3136,4356,4624,5184,6050,6400,9216,10000,10404,10816,
%U A064271 12800,13456,14400,15376,15488,16928,18496,20000,20736,23104,26912
%N A064271 Numbers k such that sigma(k) - 2k is prime.
%H A064271 Harry J. Smith, <a href="/A064271/b064271.txt">Table of n, a(n) for n = 1..1000</a>
%e A064271 n=100: sigma(100) - 2*100 = 17, a prime.
%o A064271 (PARI) j=[]; for(n=1,50000,x=sigma(n)-2*n; if(x>0 && isprime(x),j=concat(j,n))); j
%o A064271 (PARI) { n=0; for (m=1, 10^9, if (isprime(sigma(m) - 2*m), write("b064271.txt", n++, " ", m); if (n==1000, break)) ) } \\ _Harry J. Smith_, Sep 11 2009
%Y A064271 Cf. A000203, A033880.
%K A064271 easy,nonn
%O A064271 1,1
%A A064271 _Jason Earls_, Sep 23 2001