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 A267141 #25 Jun 16 2018 15:59:10 %S A267141 6,66,792,10296,144144,2162160,34594560,588107520,10585935360, %T A267141 201132771840,4022655436800,84475764172800,1858466811801600, %U A267141 42744736671436800,1025873680114483200,25646842002862080000,666817892074414080000 %N A267141 Number of weeks in n! seconds, for n >= 10. %C A267141 10! seconds = 6 weeks (exactly) %C A267141 11! seconds = 66 weeks (exactly) %C A267141 12! seconds = 792 weeks (exactly), etc. %C A267141 Demonstration of first term: %C A267141 6 w * 7 d/w * 24 h/d * 60 m/h * 60 s/m = seconds in 6 weeks = %C A267141 (2*3)*(1*7) *(3*8) * (6*10) * (3*5*4) = %C A267141 1*2*3*4*5*6*7*8*(3^2)*10 = 10! seconds %H A267141 Brady Haran, James Grime, <a href="https://www.youtube.com/watch?v=kUBIJdGsD1A">10!</a>, Numberphile video (2012) %F A267141 a(n) = 6*n!/10!. %F A267141 a(n) = 6*A051431(n-10), for n>=10. %e A267141 For n=12, a(12) = 6*(12)!/10! = 792; interpretation: 12! seconds = 792 weeks. %t A267141 f[n_] := n!/(60*60*24*7); Array[f, 17, 10] (* _Robert G. Wilson v_, Jan 12 2016 *) %o A267141 (PARI) a(n) = 6*n!/10!; \\ _Altug Alkan_, Jan 12 2016 %Y A267141 Cf. A051431. %K A267141 easy,nonn %O A267141 10,1 %A A267141 _Richard H. Sweetman_, Jan 10 2016