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A129977
Numbers m such that A119029(m) = numerator(Sum_{k=1..m} m^(k-1)/k!) is prime.
1
2, 17, 102, 112, 316, 447, 535, 820, 1396, 1475, 1650, 5575, 6486, 6832
OFFSET
1,1
COMMENTS
For n >= 1, the corresponding primes are A119029(a(n)) = {2, 1676770323947695709, ...}.
a(15) > 10000. - Lucas A. Brown, Apr 01 2021
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 *)
PROG
(PARI) for( n=1, 1000, if( ispseudoprime( numerator( sum( k=1, n, n^(k-1)/k!))), print1(n", "))) \\ M. F. Hasler, Jun 18 2007
CROSSREFS
KEYWORD
more,nonn
AUTHOR
Alexander Adamchuk, Jun 13 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
STATUS
approved