cp's OEIS Frontend

A081462 Consider the mapping f(a/b) = (a^2+b^3)/(a^3+b^2) from rationals to rationals. Starting with 1/2 (a=1, b=2) and applying the mapping to each new (reduced) rational number gives 1/2, 9/5, 103/377, ... . Sequence gives values of the denominators.

%I A081462 #4 Dec 05 2013 19:56:01
%S A081462 2,5,377,617428,19241552119440973526245,
%T A081462 6579843627298148620615676439841151690983233028443241
%N A081462 Consider the mapping f(a/b) = (a^2+b^3)/(a^3+b^2) from rationals to rationals. Starting with 1/2 (a=1, b=2) and applying the mapping to each new (reduced) rational number gives 1/2, 9/5, 103/377, ... . Sequence gives values of the denominators.
%o A081462 (PARI) {r=1/2; for(n=1,7,a=numerator(r); b=denominator(r); print1(b,","); r=(a^2+b^3)/(a^3+b^2))}
%Y A081462 Cf. A000058, A081461, A081466.
%K A081462 nonn
%O A081462 1,1
%A A081462 _Amarnath Murthy_, Mar 22 2003
%E A081462 Edited and extended by _Klaus Brockhaus_, Mar 28 2003