OFFSET
1,3
COMMENTS
Encoded primes with LSD 3 and (SOD-1)/3 non-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: 3623, with LSD 3 and (SOD-1)/3 non-integer; Then 3623/30 = 120.766, or 120, which is in the sequence, thus 3623 is prime.
MATHEMATICA
Select[Range[0, 200], PrimeQ[30#+23]&] (* Harvey P. Dale, Jul 31 2014 *)
PROG
(PARI) is(n)=isprime(30*n+23) \\ Charles R Greathouse IV, Feb 17 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Ki Punches, Mar 26 2009
EXTENSIONS
Edited by Ray Chandler, Apr 07 2009
STATUS
approved