OFFSET
1,2
REFERENCES
For the rationals r(n), a reference and a W. Lang link see A130416.
FORMULA
a(n) = denominator(r(n)), n >= 1, with r(n) := 2*Sum_{k=1..n} 1/((k^4)*binomial(2*k,k)).
PROG
(PARI) a(n) = denominator(2*sum(k=1, n, 1/((k^4)*binomial(2*k, k)))); \\ Michel Marcus, Nov 09 2019
CROSSREFS
KEYWORD
nonn,frac,easy
AUTHOR
Wolfdieter Lang, Jul 13 2007
EXTENSIONS
More terms from Michel Marcus, Nov 09 2019
STATUS
approved