OFFSET
1,2
COMMENTS
Encoded primes with LSD 9, (SOD-1)/3 integer, (LSD, least significant digit; SOD, sum of digits). Divide any such number by 30, if the whole number portion of the quotient is in the sequence, the number is prime.
EXAMPLE
Example: 3019, with LSD 9, (SOD-1)/3 integer; Then 3019/30 = 100.633, or 100, which is in the sequence, thus 3019 is prime.
PROG
(PARI) is(n)=isprime(30*n+19) \\ Charles R Greathouse IV, Feb 17 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Ki Punches, Mar 27 2009
EXTENSIONS
Edited by Ray Chandler, Apr 07 2009
STATUS
approved