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 A072986 #27 May 09 2025 00:06:09
%S A072986 1,2,6,11,24,52,113,248,553,1245,2828,6481,14963,34770,81253,190836,
%T A072986 450202,1066269,2534269,6042375,14447465,34632759,83212840,200360193,
%U A072986 483361096,1168159015,2827750519
%N A072986 Least k such that Product_{i=1..k} (prime(i) + 1) >= n*Product_{i=1..k} prime(i).
%C A072986 Least k such that A054640(k) >= n*A002110(k). - _Michel Marcus_, Jan 09 2021
%F A072986 Limit_{n->oo} a(n+1)/a(n) = e. - _Robert Gerbicz_, May 09 2008
%F A072986 a(n) = PrimePi(A072997(n)) = A000720(A072997(n)). - _Amiram Eldar_, Apr 18 2025
%t A072986 a = b = k = 1; Do[ While[a = a*Prime[k]; b = b*(Prime[k] + 1); b < n*a, k++ ]; Print[k]; k++, {n, 1, 16}]
%o A072986 (PARI) a(n)=if(n<0,0,s=1; while(prod(i=1,s, prime(i)+1)<prod(i=1,s, prime(i))*n,s++); s);
%Y A072986 Cf. A000720, A001113, A002110, A054640, A072997.
%K A072986 nonn,more
%O A072986 1,2
%A A072986 _Benoit Cloitre_, Aug 14 2002
%E A072986 Edited and extended by _Robert G. Wilson v_, Aug 20 2002
%E A072986 a(17)-a(22) from _Robert Gerbicz_, May 09 2008
%E A072986 a(23)-a(27) from _Amiram Eldar_, Apr 18 2025