A217551 Smallest numbers n, for a given s, such that s! + n^2 and (s+3)! + n^2 are squares.

1, 828, 508, 239499435, 4693095288000, 561589459200, 148245349824000

Offset: 1

Author

Robin Garcia, Oct 06 2012

Keywords

• nonn

Comments

The corresponding values of s are: 4, 8, 9, 15, 21, 24, 27.

Examples

			4! + 1 = 5^2 and 7! + 1 = 71^2.
8! + 828^2 = 852^2 and 11! + 828^2 = 6372^2.
		

Crossrefs

Cf. A217277, A217541, A217550, A217551, A217553.

Programs

PARI

for(n=4,30,a=n!;b=((n+3)*(n+2)*(n+1)-1)*a;c=divisors(b);for(i=2,#c-1,s=c[i];r=b\s;if(r