A228417 Count of the first 10^n primes which do not contain the digit 5.

1, 9, 85, 708, 6635, 60640, 535534, 4737129, 43297195, 392641522, 3536880527, 31067514571, 282635824867

Offset: 0

Author

Robert Price, Nov 09 2013

Keywords

• more
• nonn
• base
• hard

Examples

			a(1) = 9 since there are 9 primes in the first 10 (through 29) that do not contain a 5.  Namely: 2, 3, 7, 11, 13, 17, 19, 23, 29.
		

Crossrefs

Cf. A231412, A228413-A228421, A097952, A091634-A091643.

Programs

Mathematica

Table[Length[Select[Range[10^n], DigitCount[Prime[#], 10, 5] == 0 &]], {n, 0, 5}] (* Robert Price, Mar 23 2020 *)

Formula

a(n) <= 9^n. - Charles R Greathouse IV, May 21 2014

Extensions

a(12) from Lucas A. Brown, Mar 19 2024