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 A097707 #15 Mar 12 2015 07:52:40 %S A097707 1,1,3,3,3,9,63,63,567,567,6237,18711,18711,130977,392931,392931, %T A097707 392931,3536379,67191201,67191201,1411015221,15521167431,356986850913, %U A097707 1070960552739,1070960552739,1070960552739,28915934923953 %N A097707 Part of n! composed of prime factors of form 4k+3. %C A097707 log(a(n)) ~ 1/2 log n!. %H A097707 P. Pollack, <a href="http://www.math.dartmouth.edu/~ppollack/notes.pdf">Analytic and Combinatorial Number Theory</a> Course Notes, p. 75. [?Broken link] %H A097707 P. Pollack, <a href="http://alpha01.dm.unito.it/personalpages/cerruti/ac/notes.pdf">Analytic and Combinatorial Number Theory</a> Course Notes, p. 75. %o A097707 (PARI) a(n)=local(f); f=factor(n!); prod(k=1, matsize(f)[1], if(f[k, 1]%4<>3, 1, f[k, 1]^f[k, 2])) %Y A097707 Equals A097706(A000142(n)). %K A097707 nonn %O A097707 1,3 %A A097707 _Ralf Stephan_, Aug 30 2004 %E A097707 Typo in PARI code fixed by _Colin Barker_, Mar 12 2015