A257668 Primes containing a digit 7.

7, 17, 37, 47, 67, 71, 73, 79, 97, 107, 127, 137, 157, 167, 173, 179, 197, 227, 257, 271, 277, 307, 317, 337, 347, 367, 373, 379, 397, 457, 467, 479, 487, 547, 557, 571, 577, 587, 607, 617, 647, 673, 677, 701, 709, 719, 727, 733, 739, 743, 751, 757, 761

Offset: 1

Author

Vincenzo Librandi, May 03 2015

Keywords

• nonn
• base
• easy

Comments

Primes in A062675.

Subsequence of primes of A011537. - Michel Marcus, May 03 2015

Examples

			For n = 2, a(2) = 17 is the second prime containing a digit of 7.
		

Links

• Shujing Lyu, Table of n, a(n) for n = 1..100000

Crossrefs

Cf. similar sequences listed in A257667.

Cf. A011537, A062675, A166579 (subsequence).

Programs

Magma

[p: p in PrimesUpTo(800) | 7 in Intseq(p)];

Mathematica

Select[Prime[Range[150]], ! StringFreeQ[ToString[#], "7"] &]

PARI

lista(nn) = forprime(p=2, nn, if(vecsearch(vecsort(digits(p)), 7), print1(p, ", "))); \\ Altug Alkan, Apr 21 2016; corrected by Michel Marcus, Oct 30 2023

Sage

[p for p in primes(800) if 7 in p.digits(base=10)] # Bruno Berselli, May 03 2015

Formula

a(n) ~ n log n. - Charles R Greathouse IV, Nov 01 2022