A250298 Primes p such that the largest integer m such that both m and m-1 factor into primes less than or equal to p is a perfect square, m = k^2.

3, 5, 11, 13, 29, 53, 103

Offset: 1

Author

Don N. Page, Jan 15 2015

Keywords

• hard
• more
• nonn

Comments

List of primes p = A000040(i) such that A117581(i) (that is, A002072(i)+1) is a perfect square.

There are no analogous primes p < 107 for which m-1 defined above is a perfect square.

Examples

			p = 3 gives m = 3^2;
p = 5 gives m = 9^2;
p = 11 gives m = 99^2;
p = 13 gives m = 351^2;
p = 29 gives m = 13311^2;
p = 53 gives m = 1205645^2;
p = 103 gives m = 138982582999^2.
		

Crossrefs

Cf. A000040, A002072, A117581.