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A118860 Numbers n such that n-1, n+1, 2n-1, 2n+1, 3n-1, 3n+1, 4n-1 and 4n+1 are all primes. 3
21968100, 37674210, 81875220, 356467230, 416172330, 750662640, 1007393730, 1150070040, 1586271960, 1963954650, 3127171320, 3669568560, 4377895410, 4383541050, 5575083360, 5686935870, 5708418870, 7365234450, 7478474430 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

All terms are nultiples of 210, hence simpler code is possible.

LINKS

Table of n, a(n) for n=1..19.

EXAMPLE

21968100 is there because 21968099, 21968101, 43936199, 43936201, 65904299, 65904301, 87872399, 87872401 are all prime.

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

CROSSREFS

Cf. A066388, A118859.

Sequence in context: A250912 A251998 A210389 * A186595 A210076 A184375

Adjacent sequences:  A118857 A118858 A118859 * A118861 A118862 A118863

KEYWORD

nonn

AUTHOR

Labos Elemer, May 03 2006

EXTENSIONS

Edited by Don Reble, May 16 2006

STATUS

approved

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Last modified June 17 06:06 EDT 2019. Contains 324183 sequences. (Running on oeis4.)