OFFSET
1,1
COMMENTS
Primes in a(n): 2, 3, 5, 7, 11, 17, 19, 29, 31, 37, 47, 59, 61, 67, 79, 89, 107, 131, 149, 151, 157, 191, 197, 199, 227, 229, 241, 271, 277, 281,...
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
FORMULA
a(n) = A024893(n) + 2. - Michael B. Porter, Aug 11 2013
EXAMPLE
For n = 15, 3*15 - 4 = 41 is prime.
MATHEMATICA
Select[Range[300], PrimeQ[3#-4]&] (* Harvey P. Dale, Mar 30 2020 *)
PROG
(PARI) is(n)=isprime(3*n-4) \\ Charles R Greathouse IV, Mar 17 2014
CROSSREFS
KEYWORD
nonn,less,easy
AUTHOR
Irina Gerasimova, Aug 11 2013
STATUS
approved