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 A165660 #2 Jan 26 2014 15:37:09 %S A165660 1,3,2,8,13,18,27,29,23,56,7,74,44,98,67,49,171,200,217,28,137,309,17, %T A165660 116,209,448,471,174,571,629,137,739,111,793,853,318,997,1002,560,164, %U A165660 610,446,1419,1466,385,1615,1573,1633,1707,1825,946,662,2221,781,1198 %N A165660 Denominators of A007504 divided by A033955, starting from the second term of A033955. %C A165660 Conjecture: with the exception of the second term, 2 <= A165659(n)/a(n) < 3. %o A165660 (PARI) a1(n)=sum(i=1, n, prime(i)); b1(n)=sum(i=1, n, prime(n+1)%prime(i)); a(n)=if(n<0, 0, denominator(a1(n)/b1(n))); for(n=1, 50, print1(a(n) ", ")) %Y A165660 Cf. A007504, A033995, A002110, A102647, A165657, A165658, A165659 %K A165660 easy,nonn %O A165660 1,2 %A A165660 _Creighton Dement_, Sep 24 2009 %E A165660 Terms corrected by _Creighton Dement_, Oct 03 2009 %E A165660 Removed a conjecture - R. J. Mathar, Oct 09 2009 %E A165660 Typo in definition corrected by _Creighton Dement_, Oct 09 2009