The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A217551 Smallest numbers n, for a given s, such that s! + n^2 and (s+3)! + n^2 are squares. 3
 1, 828, 508, 239499435, 4693095288000, 561589459200, 148245349824000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The corresponding values of s are: 4, 8, 9, 15, 21, 24, 27. LINKS EXAMPLE 4! + 1 = 5^2 and 7! + 1 = 71^2. 8! + 828^2 = 852^2 and 11! + 828^2 = 6372^2. PROG (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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 3 01:07 EDT 2021. Contains 346429 sequences. (Running on oeis4.)