%N 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.
%C List of primes p = A000040(i) such that A117581(i) (that is, A002072(i)+1) is a perfect square.
%C There are no analogous primes p < 107 for which m-1 defined above is a perfect square.
%e p = 3 gives m = 3^2;
%e p = 5 gives m = 9^2;
%e p = 11 gives m = 99^2;
%e p = 13 gives m = 351^2;
%e p = 29 gives m = 13311^2;
%e p = 53 gives m = 1205645^2;
%e p = 103 gives m = 138982582999^2.
%Y Cf. A000040, A002072, A117581.
%A _Don N. Page_, Jan 15 2015