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.

2, 5, 377, 617428, 19241552119440973526245, 6579843627298148620615676439841151690983233028443241

Offset

1,1

Links

Table of n, a(n) for n=1..6.

Prog

(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))}

Crossrefs

Cf. A000058, A081461, A081466.

Sequence in context: A270476 A345977 A183129 * A035128 A208211 A138696

Adjacent sequences: A081459 A081460 A081461 * A081463 A081464 A081465

Keyword

nonn

Author

Amarnath Murthy, Mar 22 2003

Extensions

Edited and extended by Klaus Brockhaus, Mar 28 2003

Status

approved