OFFSET
1,2
COMMENTS
As n increases a(n)/A000217(n) tends to 0.45.
LINKS
Pierre CAMI, Table of n, a(n) for n = 1..5000
MATHEMATICA
lok[{n_, a_}]:=Module[{k=a+2, c=3*2^n}, While[!PrimeQ[c*k-1], k+=2]; {n+1, k}]; Drop[NestList[ lok, {1, 1}, 60][[;; , 2]], {2}] (* Harvey P. Dale, Sep 12 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Pierre CAMI, Apr 07 2012
STATUS
approved