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A075546 Perfect powers n such that (n-9)/2 is prime. 1
343, 1331, 12167, 29791, 42875, 79507, 103823, 300763, 357911, 857375, 1520875, 2248091, 2924207, 6436343, 9393931, 11089567, 11697083, 15069223, 15813251, 19487171, 19902511, 20796875, 22665187, 30080231, 51064811, 65450827, 77854483, 80062991, 99252847 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

n must be an odd power of a number congruent to 3 modulo 4. - Charlie Neder, Feb 11 2019

LINKS

Charlie Neder, Table of n, a(n) for n = 1..841

EXAMPLE

a(1)=7^3, a(2)=11^3, a(3)=23^3, a(4)=31^3, a(5)=35^3, a(6)=43^3, a(7)=47^3, a(8)=67^3, a(9)=71^3, a(10)=95^3, a(11)=115^3, a(12)=131^3, a(13)=143^3, a(14)=23^5 and a(15)=211^3; most are cubes.

MATHEMATICA

pp = Join[{1}, Select[ Range[10^7], Apply[GCD, Last[ Transpose[ FactorInteger[ # ]]]] > 1 & ]]; Select[pp, PrimeQ[(# - 9)/2] & ]

CROSSREFS

Sequence in context: A179147 A047739 A052084 * A167733 A167730 A250138

Adjacent sequences:  A075543 A075544 A075545 * A075547 A075548 A075549

KEYWORD

easy,nonn

AUTHOR

Zak Seidov, Oct 11 2002

EXTENSIONS

Extended by Robert G. Wilson v, Oct 14 2002

a(16)=a(29) from Charlie Neder, Feb 11 2019

STATUS

approved

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Last modified August 26 02:19 EDT 2019. Contains 326324 sequences. (Running on oeis4.)