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A158573
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Numbers n such that 30*n + 7 is prime.
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8
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0, 1, 2, 3, 4, 5, 9, 10, 11, 12, 13, 15, 16, 18, 19, 20, 24, 25, 26, 29, 30, 31, 32, 33, 36, 37, 41, 43, 44, 48, 52, 53, 54, 55, 58, 59, 62, 66, 67, 71, 76, 78, 79, 81, 82, 85, 87, 88, 89, 90, 92, 93, 95, 96, 97, 101, 102, 106, 107, 110, 115, 117, 118, 120, 121, 123, 124, 128
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,3
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COMMENTS
| Encoded primes with LSD 7 and (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.
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FORMULA
| a(n) = (A132231(n) - 7)/30 = Floor[A132231(n)/30]. - Chandler
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EXAMPLE
| Example: 3877, with LSD 7 and (SOD-1)/3 = 23 (integer); Then 3877/30 = 129.233, or 129, which is in the sequence, and thus 3877 is prime.
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CROSSREFS
| Cf. A111175, A158614, A158648, A158746, A158791, A158806, A158850.
Sequence in context: A037472 A096304 A119955 * A194398 A047603 A047362
Adjacent sequences: A158570 A158571 A158572 * A158574 A158575 A158576
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KEYWORD
| nonn
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AUTHOR
| Ki Punches (ki1212(AT)pocketmail.com), Mar 21 2009
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EXTENSIONS
| Edited by Ray Chandler (rayjchandler(AT)sbcglobal.net), Apr 07 2009
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