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A118860
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Numbers n such that n-1, n+1, 2n-1, 2n+1, 3n-1, 3n+1, 4n-1 and 4n+1 are all primes.
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2
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21968100, 37674210, 81875220, 356467230, 416172330, 750662640, 1007393730, 1150070040, 1586271960, 1963954650, 3127171320, 3669568560, 4377895410, 4383541050, 5575083360, 5686935870, 5708418870, 7365234450, 7478474430
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| All terms are nultiples of 210, hence simpler code is possible.
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EXAMPLE
| 21968100 is there because 21968099, 21968101, 43936199, 43936201, 65904299, 65904301, 87872399, 87872401 are all prime.
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MATHEMATICA
| tb={}; Do[If[(PrimeQ[n-1]&&PrimeQ[n+1])&& (PrimeQ[2*n-1]&&PrimeQ[2*n+1])&& (PrimeQ[3*n-1]&&PrimeQ[3*n+1])&& (PrimeQ[4*n-1]&&PrimeQ[4*n+1]), Print[n]; AppendTo[tb, n], {n, 21968100, 10^8, 210}]; tb
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CROSSREFS
| Cf. A066388, A118859.
Sequence in context: A189123 A206108 A034613 * A186595 A184375 A183799
Adjacent sequences: A118857 A118858 A118859 * A118861 A118862 A118863
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KEYWORD
| nonn
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AUTHOR
| Labos E. (labos(AT)ana1.sote.hu), May 03 2006
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EXTENSIONS
| Edited by Don Reble (djr(AT)nk.ca), May 16 2006
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