cp's OEIS Frontend

A261179 Take the list of positive rationals {R(n): n>=1} in the order defined by Calkin and Wilf (Recounting the Rationals, 1999); a(n) = numerator of R(prime(n)).

%I A261179 #22 Aug 12 2015 09:58:26
%S A261179 1,2,3,3,5,5,5,7,7,7,5,11,11,13,9,13,11,9,11,13,15,13,19,17,11,19,17,
%T A261179 21,19,13,7,13,19,23,29,25,23,25,27,31,29,31,13,13,25,23,31,17,23,27,
%U A261179 25,19,17,17,9,19,27,21,37,31,35,41,41,37,33,29,49,37,49,41,27,41,33,41,31,15,31,39,33,41,41,49,37,35,41,39,19,37,41,31,43,23,31,37,27,23,15,27
%N A261179 Take the list of positive rationals {R(n): n>=1} in the order defined by Calkin and Wilf (Recounting the Rationals, 1999); a(n) = numerator of R(prime(n)).
%C A261179 The list of rationals {R(n)} is essentially given by A002487(n)/A002487(n+1).
%C A261179 It appears that a(n) is always odd. This has been checked for all primes up to 999983.
%H A261179 N. Calkin and H. S. Wilf, <a href="http://www.math.upenn.edu/~wilf/website/recounting.pdf">Recounting the rationals</a>, Amer. Math. Monthly, 107 (No. 4, 2000), pp. 360-363.
%Y A261179 Subset of A002487.
%K A261179 nonn
%O A261179 1,2
%A A261179 _James Kirk Winkler_, Aug 10 2015