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 A293457 #33 Feb 11 2024 09:22:00 %S A293457 2,5,19,47,79,109,3667387 %N A293457 Primes that divide the numerator of the sum of the reciprocals of all smaller primes. %C A293457 Exhaustive search finds no more terms among the first 10^7 primes. %C A293457 Primes p that divide A024451(A000720(p)-1). - _Antti Karttunen_, Feb 08 2024 %F A293457 a(n) = A000040(1+A369972(n)). - _Antti Karttunen_, Feb 08 2024 %e A293457 Since 1/2 + 1/3 + 1/5 + 1/7 + 1/11 + 1/13 + 1/17 = 716167/510510 and 19 divides 716167, 19 is in the sequence. %e A293457 Since there are no primes less than 2, the sum of their reciprocals is 0/1, and as 2 divides 0, it is therefore included as the first term of this sequence. - _Antti Karttunen_, Feb 08 2024 %o A293457 (PARI) lista(nn) = my(s = 0); forprime(p=2, nn, if (!(numerator(s) % p), print1(p, ", ")); s += 1/p; ); \\ _Michel Marcus_, Oct 09 2017, edited for the new, more inclusive definition by _Antti Karttunen_, Feb 08 2024 %Y A293457 Cf. A000040, A000720, A024451, A120289, A369972, A369973. %K A293457 more,nonn %O A293457 1,1 %A A293457 _Logan J. Kleinwaks_, Oct 09 2017 %E A293457 Relaxed the definition to include 2 as the first term - _Antti Karttunen_, Feb 08 2024