A231792 Count of the first 10^n primes containing at least one 5's digit.

1, 15, 292, 3365, 39360, 464466, 5262871, 56702805, 607358478, 6463119473, 68932485429

Offset: 1

Author

Robert Price, Nov 13 2013

Keywords

• more
• nonn
• base

Examples

			a(2)=15 because there are 15 primes not greater than 541 (the 100th prime) that contain a 5's digit.  Namely: 5, 53 59, 151, 157, 251, 257,  353, 359, 457, 503, 509, 521, 523, 541.
		

Crossrefs

Cf. A231726-A231790, A231792-A231796, A091634-A091643, A231412, A228413-A228421.

Programs

Mathematica

cnt = 0; Table[Do[p = Prime[k]; If[MemberQ[IntegerDigits[p], 5], cnt++], {k, 10^(n - 1) + 1, 10^n}]; cnt, {n, 5}] (* T. D. Noe, Nov 13 2013 *)

Formula

a(n) ~ 10^n. - Charles R Greathouse IV, May 21 2014