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 A158806 Numbers n such that 30*n + 19 is prime. 9
 0, 2, 3, 4, 6, 7, 11, 12, 13, 14, 16, 20, 23, 24, 25, 27, 28, 30, 33, 34, 35, 37, 41, 42, 46, 47, 48, 49, 51, 52, 53, 55, 56, 58, 59, 62, 66, 67, 69, 72, 74, 75, 79, 84, 88, 89, 90, 91, 100, 101, 102, 103, 105, 107, 108, 110, 115, 116, 117, 118, 123, 124, 125, 129, 130 (list; graph; refs; listen; history; text; internal format)
 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. LINKS Table of n, a(n) for n=1..65. FORMULA a(n) = (A132234(n) - 19)/30 = Floor[A132234(n)/30]. - Chandler 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 Cf. A111175, A158573, A158614, A158648, A158746, A158791, A158850. Sequence in context: A050679 A342684 A344625 * A184966 A018723 A088412 Adjacent sequences: A158803 A158804 A158805 * A158807 A158808 A158809 KEYWORD nonn AUTHOR Ki Punches, Mar 27 2009 EXTENSIONS Edited by Ray Chandler, Apr 07 2009 STATUS approved

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Last modified May 27 16:57 EDT 2024. Contains 372880 sequences. (Running on oeis4.)