A228414 Count of the first 10^n primes which do not contain the digit 2.

0, 7, 77, 697, 6497, 55552, 512100, 4710641, 42205969, 341224891, 2787791578, 22971326749, 190650687957

Offset

0,2

Links

Table of n, a(n) for n=0..12.

Formula

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

Example

a(1) = 7 since there are 7 primes less than 29 (the 10th prime) that do not contain a 2.  Namely: 3, 5, 7, 11, 13, 17, 19.

Mathematica

Table[Length[Select[Range[10^n], DigitCount[Prime[#], 10, 2] == 0 &]], {n, 0, 5}] (* Robert Price, Mar 23 2020 *)

Crossrefs

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

Sequence in context: A268958 A068667 A261741 * A043042 A191465 A229281

Adjacent sequences: A228411 A228412 A228413 * A228415 A228416 A228417

Keyword

more,nonn,base,hard

Author

Robert Price, Nov 09 2013

Extensions

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

Status

approved