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A271718 Numbers n such that n*(n+1)^n - 1 is prime. 1
2, 3, 7, 14, 43, 81, 943, 1621 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The corresponding primes are a subset of the generalized Woodall primes (A210340).

LINKS

Table of n, a(n) for n=1..8.

EXAMPLE

14 is a member because 14*15^14 - 1 = 408700964355468749 is a prime number.

MATHEMATICA

Select[Range[10^3], PrimeQ[# (# + 1)^# - 1] &] (* Michael De Vlieger, Apr 12 2016 *)

PROG

(PARI) for(n=1, 10^10, ispseudoprime(n*(n+1)^n-1)&&print1(n, ", "))

CROSSREFS

Cf. A191568, A210340.

Sequence in context: A113182 A165433 A238728 * A222626 A006627 A077161

Adjacent sequences:  A271715 A271716 A271717 * A271719 A271720 A271721

KEYWORD

nonn,hard,more

AUTHOR

Jeppe Stig Nielsen, Apr 12 2016

STATUS

approved

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Last modified January 23 01:37 EST 2021. Contains 340384 sequences. (Running on oeis4.)