OFFSET
1,1
EXAMPLE
6 is there because 5, 7, 11, 13, 17, 19 are all prime.
MATHEMATICA
Select[Range[25*10^6], AllTrue[Flatten[{#+{1, -1}, 2#+{1, -1}, 3#+{1, -1}}], PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Sep 13 2016 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, May 03 2006
EXTENSIONS
Edited by Don Reble, May 16 2006
a(26)-a(28) from Jon E. Schoenfield, Dec 07 2021
STATUS
approved