OFFSET
1,3
COMMENTS
MAPLE
select(x-> denom(x)=1, [k!/(k*(k+1)/2)$k=1..30])[]; # Alois P. Heinz, Dec 11 2020
MATHEMATICA
Select[Table[(n - 1)!/((n (n - 1))/2), {n, 2, 50}], IntegerQ[#] &] (* Geoffrey Critzer, May 02 2015 *)
PROG
(PARI) for(n=1, 50, r=2*(n-1)!/(n+1); if(denominator(r)==1, print1(r, ", ")))
CROSSREFS
KEYWORD
nonn
AUTHOR
Rick L. Shepherd, Jun 09 2005
EXTENSIONS
Offset corrected by Alois P. Heinz, Dec 11 2020
STATUS
approved