OFFSET
1,1
LINKS
I. Nemes et al., How to do Monthly problems with your computer, Amer. Math. Monthly, 104 (1997), 505-519.
MATHEMATICA
Table[(2n)!HarmonicNumber[n], {n, 20}] (* Harvey P. Dale, Sep 27 2013 *)
PROG
(PARI) a(n) = (2*n)!*sum(k=1, n, 1/k); \\ Michel Marcus, Jul 11 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved