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 A336297 #21 Jul 23 2020 14:10:03 %S A336297 2,61,97,113,151,173,241,277,317,353,389,449,457,593,601,607,653,673, %T A336297 683,727,733,797,907,929,941,947,953,977,997,1021,1051,1087,1153,1181, %U A336297 1193,1217,1249,1307,1321,1361,1373,1409,1433,1489,1493,1523,1553,1579,1597,1609,1627 %N A336297 Prime numbers p such that equation x = p*sopf(x) (where sopf(x) is the sum of distinct prime factors of x) has exactly 1 solution in positive integers. %H A336297 Vladimir Letsko, <a href="https://dxdy.ru/post1257616.html#p1257616">Mathematical Marathon, Problem 227</a> (in Russian). %e A336297 4 is the unique integer x such that x = 2*sopf(x), a prime, so 2 is a term. %Y A336297 Cf. A008472, A336098, A336099, A336296. %K A336297 nonn %O A336297 1,1 %A A336297 _Vladimir Letsko_, Jul 16 2020