A158614 Numbers n such that 30*n + 11 is prime.

0, 1, 2, 3, 4, 6, 8, 9, 10, 13, 14, 15, 16, 17, 21, 23, 25, 27, 29, 30, 31, 32, 34, 35, 36, 38, 39, 43, 45, 48, 49, 50, 52, 53, 57, 60, 62, 63, 64, 69, 70, 71, 78, 79, 80, 81, 84, 86, 87, 90, 91, 93, 95, 100, 101, 106, 107, 108, 112, 115, 116, 119, 122, 123, 125, 127, 128

Offset: 1

Author

Ki Punches, Mar 22 2009, Mar 29 2009

Keywords

• nonn

Comments

Encoded primes with LSD 1 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.

Examples

			Example: 3191, with LSD 1 and (SOD-1)/3 = 4.33 (non-integer); Then 3191/30=106.367, or 106 which is in the sequence, thus 3191 is prime.
		

Links

• Ivan Neretin, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A111175, A158573, A158648, A158746, A158791, A158806, A158850.

Programs

Mathematica

Select[Range[0,130],PrimeQ[30#+11]&] (* Harvey P. Dale, Jul 26 2011 *)

PARI

is(n)=isprime(30*n+11) \\ Charles R Greathouse IV, Feb 17 2017

Formula

a(n) = (A132232(n) - 11)/30 = floor(A132232(n)/30). - Ray Chandler, Apr 07 2009

Extensions

Edited by Ray Chandler, Apr 07 2009