OFFSET
1,2
COMMENTS
FORMULA
a(n) = denominator(r(n)), n >= 1, with the rationals r(n) defined above.
PROG
(PARI) a(n) = denominator(2*sum(j=1, n, 1/(j*binomial(2*j, j)))); \\ Michel Marcus, Nov 09 2019
CROSSREFS
KEYWORD
nonn,frac,easy
AUTHOR
Wolfdieter Lang, Jul 13 2007
STATUS
approved