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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. 1

%I

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

%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.

%K hard,more,nonn

%O 1,1

%A _Don N. Page_, Jan 15 2015

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Last modified January 17 06:12 EST 2022. Contains 350378 sequences. (Running on oeis4.)