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A275631 Primes p such that the product of the distinct prime factors of p^2-1 is less than p. 1
3, 7, 17, 31, 97, 127, 251, 449, 487, 577, 1151, 1249, 1567, 1999, 2663, 4801, 4999, 7937, 8191, 12799, 13121, 13183, 15551, 31249, 31751, 32257, 33857, 35153, 39367, 65537, 79201, 81919, 85751, 115249, 117127, 124001, 126001, 131071 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Dana Jacobsen, Table of n, a(n) for n = 1..340

MATHEMATICA

Select[Prime[Range[13000]], Times@@FactorInteger[#^2-1][[All, 1]]<#&] (* Harvey P. Dale, Apr 10 2017 *)

PROG

(Perl) use ntheory ":all"; forprimes { say if vecprod(map { $_->[0] } factor_exp($_**2-1)) < $_ } 1e6; # Dana Jacobsen, Aug 09 2016

CROSSREFS

Cf. A007947, A275630.

Sequence in context: A292446 A045425 A099983 * A048860 A233930 A292447

Adjacent sequences:  A275628 A275629 A275630 * A275632 A275633 A275634

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Aug 07 2016, following a suggestion from J. M. Bergot.

EXTENSIONS

Terms a(10) and beyond from Dana Jacobsen, Aug 09 2016

STATUS

approved

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Last modified October 14 12:31 EDT 2019. Contains 328006 sequences. (Running on oeis4.)