OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
a(1)=59 because 2*59-1=117, 2*59+1=119, 2*59-3=115, 2*59+3=121 are all composites.
MATHEMATICA
okQ[n_]:=Union[PrimeQ[{2n+1, 2n-1, 2n+3, 2n-3}]]=={False}; Select[Prime[Range[250]], okQ] (* Harvey P. Dale, Feb 07 2010 *)
Select[Prime[Range[300]], AllTrue[2#+{1, 3, -1, -3}, CompositeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Feb 20 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Jan 24 2010
EXTENSIONS
Corrected and extended by Harvey P. Dale, Feb 07 2010
STATUS
approved