OFFSET
1,1
EXAMPLE
a(3) = 24 = 2*3*4 = 2*12.
a(6) = 5040 = 2*3*4*5*6*7 = 12*420 = 56*90.
MAPLE
N:= 10^10: # to get all terms <= N
A072389:= {seq(seq(n*(n+1)*m*(m+1), m=n..floor((sqrt(1+4*N/(n*(n+1))-1)/2))), n=1..floor((sqrt(1+2*N)-1)/2))}:
for n from 1 do
x:= n!;
for m from 1 while x <= N and not member(x, A072389) do
x:= x*(n+m)/m
od;
if x > N then break fi;
A[n]:= x;
od:
seq(A[i], i=1..n-1); # Robert Israel, Jun 16 2016
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Gionata Neri, Jun 12 2016
EXTENSIONS
a(14) from Robert Israel, Jun 16 2016
STATUS
approved