cp's OEIS Frontend

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.

A242050 Denominator of A242035(n) / A246053(floor(n/2)).

Original entry on oeis.org

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, 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, 1, 1, 1, 1, 1, 1, 1, 5, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
Offset: 0

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Author

Peter Luschny, Aug 17 2014

Keywords

Comments

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.

Examples

			a(34) = 1 because A246053(17) divides A242035(34).
a(35) = 7 because A242035(35)/A246053(17) = 8416843291197378595121525029762095062482279733/7.
		

Crossrefs

Programs

  • Sage
    h = lambda x: zeta(2*x)*(4^x-2)
    r = lambda n: h((n+1)//2)*h(n//2)/h(n)
    A242050 = lambda n: (r(n).numerator()/r(n//2).denominator()).denominator()
    [A242050(n) for n in range(1000)]