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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
3, 5, 11, 13, 29, 53, 103 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

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.

LINKS

Table of n, a(n) for n=1..7.

EXAMPLE

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.

Sequence in context: A095082 A265396 A216553 * A260224 A105071 A089251

Adjacent sequences:  A250295 A250296 A250297 * A250299 A250300 A250301

KEYWORD

hard,more,nonn

AUTHOR

Don N. Page, Jan 15 2015

STATUS

approved

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Last modified November 30 18:40 EST 2021. Contains 349424 sequences. (Running on oeis4.)