OFFSET
1,1
COMMENTS
Corresponding values of k in A179443.
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
select(t -> not isprime((t-1)/10) and not isprime(t), [seq(i, i=21..10001, 10)]); # Robert Israel, Jun 11 2019
MATHEMATICA
Select[10#+1&/@Select[Range[100], !PrimeQ[#]&], !PrimeQ[#]&] (* Harvey P. Dale, Dec 01 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Jul 14 2010
EXTENSIONS
More terms from Robert Israel, Jun 11 2019
STATUS
approved