OFFSET
1,2
COMMENTS
If K is a term and K-1 is the neighboring prime then it must be a Mersenne prime.
Conjecture: sequence is infinite.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..322 (all terms up to 10 million)
MATHEMATICA
Join[{1}, Select[Range[45000], GCD@@FactorInteger[#][[All, 2]]>1 && AnyTrue[ #+{1, -1}, PrimeQ]&]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Nov 05 2020 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Sep 27 2003
EXTENSIONS
Corrected and extended by Ray Chandler, Sep 28 2003
Offset changed by Andrew Howroyd, Sep 22 2024
STATUS
approved