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A166580 Prime numbers containing the string 222. 9
2221, 12227, 22229, 22247, 22259, 22271, 22273, 22277, 22279, 22283, 22291, 42221, 42223, 42227, 52223, 72221, 72223, 72227, 72229, 82223, 92221, 92227, 102229, 112223, 122201, 122203, 122207, 122209, 122219, 122231, 122251, 122263, 122267 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

FORMULA

a(n) ~ n log n. - Charles R Greathouse IV, Jun 20 2014

MATHEMATICA

p222Q[n_] := Module[{idn = IntegerDigits[n]}, MemberQ[Partition[idn, 3, 1], {2, 2, 2}]]; Select[Prime[Range[15000]], p222Q] (* Vincenzo Librandi Sep 14 2012 *)

Select[Prime[Range[12000]], SequenceCount[IntegerDigits[#], {2, 2, 2}]>0&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Nov 08 2017 *)

PROG

(PARI) contains(n, k)=my(N=digits(n), K=digits(k)); for(i=0, #N-#K, for(j=1, #K, if(N[i+j]!=K[j], next(2))); return(1)); 0

is(n)=isprime(n) && contains(n, 222) \\ Charles R Greathouse IV, Jun 20 2014

CROSSREFS

Cf. A166571 - A166573, A166579, A166581, A166582.

Sequence in context: A092992 A210712 A260175 * A091189 A046443 A257826

Adjacent sequences:  A166577 A166578 A166579 * A166581 A166582 A166583

KEYWORD

nonn,base

AUTHOR

Vincenzo Librandi, Nov 01 2009

STATUS

approved

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Last modified September 18 16:22 EDT 2020. Contains 337170 sequences. (Running on oeis4.)