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 A140761 #12 Nov 02 2020 20:38:54 %S A140761 2,5,19,41,83,163,167,179,191,223,229,241,263,269,271,317,337,349,367, %T A140761 389,433,463,491,521,701,719,757,809,823,829,859,877,883,919,941,971, %U A140761 991,997,1021,1033,1049,1091,1153,1181,1193,1223,1291,1301,1319,1327,1361 %N A140761 Primes p(j) = A000040(j), j>=1, such that p(1)*p(2)*...*p(j) is an integral multiple of p(1)+p(2)+...+p(j). %H A140761 Amiram Eldar, <a href="/A140761/b140761.txt">Table of n, a(n) for n = 1..10000</a> %F A140761 Find integral quotients of products of consecutive primes divided by their sum. %F A140761 a(n) = A000040(A051838(n)). - _R. J. Mathar_, Jun 09 2008 %e A140761 a(2) = 5 because it is the last consecutive prime in the run 2*3*5 = 30 and 2+3+5 = 10; since 30/10 = 3, it is the first integral quotient. %t A140761 seq = {}; sum = 0; prod = 1; p = 1; Do[p = NextPrime[p]; prod *= p; sum += p; If[Divisible[prod, sum], AppendTo[seq, p]], {200}]; seq (* _Amiram Eldar_, Nov 02 2020 *) %Y A140761 Cf. A002110, A007504, A051838, A116536, A140763, A159578. %K A140761 easy,nonn %O A140761 1,1 %A A140761 _Enoch Haga_, May 28 2008 %E A140761 Edited by _R. J. Mathar_, Jun 09 2008 %E A140761 a(1) added by _Amiram Eldar_, Nov 02 2020