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A054462 Numbers n such that (n+1)^n + n^(n-1) is prime. 0
1, 2, 3, 8, 9, 15, 16, 219 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

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

MATHEMATICA

Select[Range[1000], PrimeQ[(# + 1)^# + #^(# - 1)] &] (* Vincenzo Librandi Sep 27 2012 *)

PROG

(PARI) xp1toxp1(n)= { sr=0; forstep(x=2, n, 1, y=(x+1)^x + x^(x-1); if(ispseudoprime(y), print(x" "y" "); sr+= 1.0/y; ) ); print(); print(sr) }

CROSSREFS

Sequence in context: A309423 A029787 A246396 * A101471 A137471 A051209

Adjacent sequences:  A054459 A054460 A054461 * A054463 A054464 A054465

KEYWORD

nonn

AUTHOR

Cino Hilliard, Aug 30 2003

EXTENSIONS

Inserted a(1)=1 by Vincenzo Librandi, Sep 27 2012

STATUS

approved

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Last modified January 20 10:33 EST 2022. Contains 350472 sequences. (Running on oeis4.)