A097573 Denominator of f(n) where f(1) = 1, f(n+1) = n^2/f(n) + f(n)/n^2 + 2.

1, 1, 1, 36, 97344, 2161134144, 1111852196419369017600, 462046200367699618749878135899012178386694400, 117224333139662940653070504914857570420089294144957107957142671212206786775390019069002137600

Offset

1,4

Links

Table of n, a(n) for n=1..9.

Y. Chen and others, Variation of a Ukrainian Olympiad Problem: Problem 10982, Amer. Math. Monthly, 111 (No. 7, 2004), 631-632.

Formula

f(n) -> n + 1/2.

Example

1, 4, 4, 169/36, 555025/97344, 14291007025/2161134144, ...

Crossrefs

Cf. A097573.

Sequence in context: A212327 A053945 A357804 * A133015 A203270 A185960

Adjacent sequences: A097570 A097571 A097572 * A097574 A097575 A097576

Keyword

nonn,frac

Author

N. J. A. Sloane, Aug 29 2004

Status

approved