|
|
A274187
|
|
Least number that is the product of n consecutive positive numbers and the product of 2 oblong numbers.
|
|
0
|
|
|
4, 12, 24, 24, 120, 5040, 5040, 362880, 362880, 3628800, 39916800, 6227020800, 6227020800, 3379030566912000
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
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:
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,more
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|