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 A109757 #8 Dec 15 2017 17:36:55 %S A109757 1,3,6,14,20,21,26,34,37,39,40,47,51,54,61,62,72,74,77,82,83,86,113, %T A109757 115,118,127,139,179 %N A109757 Numbers n such that (10's complement factorial of n) + 1 is semiprime. %o A109757 (PARI) comp(n)=10^#Str(n)-n %o A109757 is(n)=bigomega(prod(k=1,n,comp(k))+1)==2 \\ _Charles R Greathouse IV_, Jul 10 2011 %Y A109757 Cf. A110396, A109616. %K A109757 nonn,base %O A109757 1,2 %A A109757 _Jason Earls_, Aug 12 2005 %E A109757 More terms from _Sean A. Irvine_, Jul 10 2011