A243531 Prime numbers containing the string 15.

151, 157, 1151, 1153, 1511, 1523, 1531, 1543, 1549, 1553, 1559, 1567, 1571, 1579, 1583, 1597, 2153, 4153, 4157, 4159, 5153, 6151, 7151, 7159, 9151, 9157, 10151, 10159, 11159, 11503, 11519, 11527, 11549, 11551, 11579, 11587, 11593, 11597, 12157, 13151, 13159

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

Select[Prime[Range[2000]], !StringFreeQ[ToString[#], "15" ] &]
Select[Prime[Range[2000]], SequenceCount[IntegerDigits[#], {1, 5}]>0&] (* Harvey P. Dale, Sep 19 2023 *)

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

Crossrefs

Cf. similar sequences listed in A243529.

Sequence in context: A336777 A250312 A180554 * A139505 A095745 A112796

Adjacent sequences: A243528 A243529 A243530 * A243532 A243533 A243534

Keyword

nonn,base,less

Author

Vincenzo Librandi, Jun 06 2014

Status

approved