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A124272 Primes in A124271, or primes of the form Sum_{i=1..n} (prime(i)^n - 1)/(prime(i) - 1). 1
7, 1469991559, 2994181661163361882651 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The corresponding n are 2, 8, 14, ...

LINKS

Table of n, a(n) for n=1..3.

EXAMPLE

7 is a term because A124271(2) = 7 is prime.

MATHEMATICA

Do[f=Sum[(Prime[i]^n-1)/(Prime[i]-1), {i, 1, n}]; If[PrimeQ[f], Print[{n, f}]], {n, 1, 100}]

CROSSREFS

Cf. A124271.

Sequence in context: A116257 A075984 A109300 * A128820 A067485 A180225

Adjacent sequences:  A124269 A124270 A124271 * A124273 A124274 A124275

KEYWORD

bref,hard,more,nonn

AUTHOR

Alexander Adamchuk, Oct 23 2006

STATUS

approved

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Last modified October 22 04:25 EDT 2019. Contains 328315 sequences. (Running on oeis4.)