

A222961


Numbers n such that 2*n + {3, 5, 9, 11, 15, 21} are all primes.


1



1, 4, 739, 82849, 163069, 330544, 511249, 534349, 623179, 730699, 958864, 1529434, 2077954, 2109139, 2763499, 4172074, 5067199, 5882524, 5950249, 6532159, 7860409, 7880044, 9252184, 9368419, 9564769, 9605719, 10024984
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OFFSET

1,2


COMMENTS

After 1, a(n) is congruent to 4 or 9 (mod 10), this means that a(n) is of the form 5k1. Clearly, each term is not divisible by 3, 7 and 11.


LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..100


MATHEMATICA

Select[Range[7000000], Union[PrimeQ[2 # +{3, 5, 9, 11, 15, 21}]]=={True}&]


PROG

(MAGMA) [n: n in [1..11000000]  forall{2*n+k: k in [3, 5, 9, 11, 15, 21]  IsPrime(2*n+k)}];


CROSSREFS

Cf. A136162.
Sequence in context: A134579 A090588 A053986 * A160737 A128846 A332174
Adjacent sequences: A222958 A222959 A222960 * A222962 A222963 A222964


KEYWORD

nonn


AUTHOR

Vincenzo Librandi, Mar 13 2013


STATUS

approved



