OFFSET
1,1
COMMENTS
This does not count x^2 and (-x)^2 as distinct, nor does it count 0! and 1! as distinct.
a(10) > 10^30 if it exists. - David A. Corneth, Dec 11 2022
EXAMPLE
145 = 5^2 + 5! = 11^2 + 4! = 12^2 + 1!.
PROG
(Python) import math
for x in range(1, 120000000):
total = 0
prod = 1
factInc = 2
while prod <= x:
sq = math.sqrt(x - prod)
if sq % 1 == 0:
total = total + 1
prod = prod * factInc
factInc = factInc + 1
if total == 3:
print(x)
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Walter Robinson, Dec 11 2022
EXTENSIONS
a(5)-a(9) from David A. Corneth, Dec 11 2022
STATUS
approved