A166579 Prime numbers containing the string 17.

17, 173, 179, 317, 617, 1117, 1171, 1217, 1709, 1721, 1723, 1733, 1741, 1747, 1753, 1759, 1777, 1783, 1787, 1789, 2017, 2179, 2417, 2617, 2917, 3217, 3517, 3617, 3917, 4177, 4217, 4517, 4817, 5171, 5179, 5417, 5717, 6173, 6217, 6317, 6917, 7177, 7417

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

Maple

isA166579 := proc(n) local dgs, wrks; if isprime(n) then dgs := convert(n, base, 10) ; wrks := false; for i from 1 to nops(dgs)-1 do if op(i, dgs) = 7 and op(i+1, dgs) = 1 then return true; end if; od: return false; else false; end if; end proc: for n from 1 to 8000 do if isA166579(n) then printf("%d, ", n) ; end if; od: # R. J. Mathar, Nov 30 2009

Mathematica

p17Q[n_] := Module[{idn = IntegerDigits[n]}, MemberQ[Partition[idn, 2, 1], {1, 7}]]; Select[Prime[Range[1000]], p17Q] (* Vincenzo Librandi Sep 14 2012 *)
Select[Prime[Range[1000]], SequenceCount[IntegerDigits[#], {1, 7}]>0&] (* Harvey P. Dale, Apr 18 2022 *)

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, 17) \\ Charles R Greathouse IV, Jun 20 2014

Crossrefs

Cf. A166571 - A166573, A166580, A166581, A166582.

Sequence in context: A022645 A326211 A164747 * A142169 A142515 A011549

Adjacent sequences: A166576 A166577 A166578 * A166580 A166581 A166582

Keyword

nonn,base,less

Author

Vincenzo Librandi, Nov 01 2009

Status

approved