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 A242050 #10 Aug 18 2014 16:57:49 %S A242050 2,2,2,2,1,7,1,2,1,1,1,5,1,1,7,10,1,7,1,1,1,1,3,7,1,5,1,1,1,1,1,2,1,1, %T A242050 1,7,1,1,1,1,1,1,1,1,1,1,1,1,1,7,1,1,1,1,1,5,1,1,3,1,1,1,1,62,1,1,1,1, %U A242050 1,1,1,1,1,1,1,5,1,1,1,1,1,1,1,1,1,1,1 %N A242050 Denominator of A242035(n) / A246053(floor(n/2)). %C A242050 Let h(x) = zeta(2*x)*(4^x-2) and r(n) = h([(n+1)/2])*h([n/2])/ h(n). Then the denominator of r([n/2]) almost divides the numerator of r(n), where 'a almost divides b' means that a divides b or the denominator of the quotient b/a (reduced to lowest terms) is very small compared to the size of b. %H A242050 Peter Luschny, <a href="/A242050/b242050.txt">Table of n, a(n) for n = 0..10000</a> %e A242050 a(34) = 1 because A246053(17) divides A242035(34). %e A242050 a(35) = 7 because A242035(35)/A246053(17) = 8416843291197378595121525029762095062482279733/7. %o A242050 (Sage) %o A242050 h = lambda x: zeta(2*x)*(4^x-2) %o A242050 r = lambda n: h((n+1)//2)*h(n//2)/h(n) %o A242050 A242050 = lambda n: (r(n).numerator()/r(n//2).denominator()).denominator() %o A242050 [A242050(n) for n in range(1000)] %Y A242050 Cf. A242035, A246053. %K A242050 nonn %O A242050 0,1 %A A242050 _Peter Luschny_, Aug 17 2014