A129977 Numbers m such that A119029(m) = numerator(Sum_{k=1..m} m^(k-1)/k!) is prime.

2, 17, 102, 112, 316, 447, 535, 820, 1396, 1475, 1650, 5575, 6486, 6832

Offset: 1

Author

Alexander Adamchuk, Jun 13 2007

Keywords

• more
• nonn

Comments

For n >= 1, the corresponding primes are A119029(a(n)) = {2, 1676770323947695709, ...}.

a(15) > 10000. - Lucas A. Brown, Apr 01 2021

Links

• Lucas A. Brown, A129977.py

Crossrefs

Cf. A119029, A120266, A120267.

Programs

Mathematica

Do[ f=Numerator[ Sum[ n^(k-1)/k!, {k, 1, n} ] ]; If[ PrimeQ[f], Print[{n,f}] ], {n,1,316} ]
Select[Range[2000],PrimeQ[Numerator[Sum[#^(k-1)/k!,{k,#}]]]&] (* Harvey P. Dale, Jun 15 2019 *)

PARI

for( n=1,1000, if( ispseudoprime( numerator( sum( k=1,n,n^(k-1)/k!))), print1(n", "))) \\ M. F. Hasler, Jun 18 2007

Extensions

Edited and extended (a(6)..a(8)) by M. F. Hasler, Jun 18 2007

More terms from Ryan Propper, Jan 12 2008

Various sections edited by Petros Hadjicostas, May 12 2020

a(12)-a(14) from Lucas A. Brown, Apr 01 2021