OFFSET
1,4
REFERENCES
Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, page 19.
LINKS
Clark Kimberling, Table of n, a(n) for n = 1..1000
EXAMPLE
Let w(n) = 2n/v(n)^2. The first 7 values of w are 4, 6, 32/9, 40/9, 256/75, 896/225, 4096/1225, with approximations 4., 6., 3.55556, 4.44444, 3.41333, 3.98222, 3.34367; w(1000) = 3.14316..., w(10000) = 3.14175..., w(20000) = 3.14167... .
MAPLE
v:= proc(n) v(n):= `if`(n<3, n-1, v(n-1)/(n-2)+v(n-2)) end:
a:= n-> denom(2*n/v(n)^2):
seq(a(n), n=2..30); # Alois P. Heinz, Mar 12 2014
MATHEMATICA
CROSSREFS
KEYWORD
nonn,frac,easy
AUTHOR
Clark Kimberling, Mar 12 2014
STATUS
approved