This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

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