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A101790 Numbers n such that 4n-1, 8n-1 and 16n-1 are primes. 6
3, 45, 90, 180, 255, 258, 363, 378, 453, 483, 615, 675, 705, 873, 885, 978, 1350, 1533, 1770, 1788, 2673, 2793, 2868, 3030, 3225, 3240, 4203, 4290, 4548, 4830, 4998, 5103, 5253, 5295, 5568, 5775, 5955, 6060, 6138, 6870, 7383, 7713, 8133, 8370, 8580, 9000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..46.

EXAMPLE

4*3-1=11, 8*3-1=23 and 16*3-1=47 are primes, so the first entry is 3.

PROG

(MAGMA) [n: n in [0..10000] | IsPrime(4*n-1) and IsPrime(8*n-1) and IsPrime(16*n-1)] [From Vincenzo Librandi, Nov 17 2010]

CROSSREFS

Cf. A002515, A101791, A101792, A101793.

Sequence in context: A178337 A161589 A079038 * A124494 A075320 A071968

Adjacent sequences:  A101787 A101788 A101789 * A101791 A101792 A101793

KEYWORD

easy,nonn

AUTHOR

Douglas Stones (dssto1(AT)student.monash.edu.au), Dec 16 2004

STATUS

approved

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Last modified April 27 06:52 EDT 2017. Contains 285508 sequences.