

A158648


Numbers n such that 30*n + 17 is prime.


9



0, 1, 3, 4, 5, 6, 7, 8, 10, 11, 15, 18, 19, 20, 21, 22, 26, 27, 28, 29, 31, 32, 36, 39, 40, 42, 43, 45, 47, 49, 53, 54, 55, 56, 59, 61, 62, 63, 66, 67, 69, 73, 74, 75, 76, 78, 80, 81, 82, 88, 89, 92, 94, 96, 97, 98, 104, 105, 108, 111, 113, 115, 117, 118, 120, 122, 125, 126
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OFFSET

1,3


COMMENTS

Encoded primes with LSD 7 and (SOD1)/3 noninteger, (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.


LINKS

Table of n, a(n) for n=1..68.


FORMULA

a(n) = (A039949(n)  17)/30 = Floor[A039949(n)/30].  Chandler


EXAMPLE

Example: 3557, with LSD 7 and (SOD1)/3 = 6.333 (noninteger); Then 7557/30 = 118.566, or 118 which is in the sequence, and thus 3557 is prime.


MATHEMATICA

Select[Range[0, 200], PrimeQ[30#+17]&] (* Harvey P. Dale, Mar 21 2018 *)


PROG

(PARI) is(n)=isprime(30*n+17) \\ Charles R Greathouse IV, Feb 17 2017


CROSSREFS

Cf. A111175, A158573, A158614, A158746, A158791, A158806, A158850.
Sequence in context: A026482 A232803 A117346 * A039078 A073632 A066378
Adjacent sequences: A158645 A158646 A158647 * A158649 A158650 A158651


KEYWORD

nonn


AUTHOR

Ki Punches, Mar 23 2009


EXTENSIONS

Edited by Ray Chandler, Apr 07 2009


STATUS

approved



