Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A125707
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A125707 Numbers n such that A024528(n) is prime. +0
2
1, 2, 3, 4, 5, 7, 14, 15, 17, 23, 32, 36, 42, 309, 1384, 1588 (list; graph; listen)
OFFSET

1,2

COMMENT

A024528(n) is the numerator of 1 + Sum[ 1/Prime[k], {k,1,n} ], or n-th elementary symmetric function of {1, prime(1), prime(2), ..., prime(n-1)}.

MATHEMATICA

f=1; Do[p=Prime[n]; f=f+1/p; g=Numerator[f]; If[PrimeQ[g], Print[{n, p, g}]], {n, 1, 50}]

CROSSREFS

Cf. A024528, A109628.

Sequence in context: A137357 A100676 A066661 this_sequence A039060 A092065 A044955

Adjacent sequences: A125704 A125705 A125706 this_sequence A125708 A125709 A125710

KEYWORD

hard,more,nonn

AUTHOR

Alexander Adamchuk (alex(AT)kolmogorov.com), Feb 01 2007

EXTENSIONS

3 more terms from Ryan Propper (rpropper(AT)cs.stanford.edu), Feb 11 2008

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified November 27 22:38 EST 2009. Contains 167602 sequences.


AT&T Labs Research