OFFSET
1,1
COMMENTS
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
MAPLE
filter:= n -> isprime(n) and nops(numtheory:-factorset((n+1)/2))=1:
select(filter, [seq(i, i=3..10000, 2)]); # Robert Israel, Feb 20 2024
MATHEMATICA
Select[Prime[Range[20000]], Length[FactorInteger[(#+1)/2]]==1&]
PROG
(PARI) is_A178490(n) = isprime(n) & omega((n+1)\2)==1
CROSSREFS
KEYWORD
nonn
AUTHOR
Farideh Firoozbakht and M. F. Hasler, Oct 09 2010
STATUS
approved