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A231790 Count of the first 10^n primes containing at least one 4's digit. 10
0, 25, 279, 3363, 39395, 485191, 5269618, 56745409, 607655311, 6578438247, 68950399755 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
a(n) ~ 10^n. - Charles R Greathouse IV, May 21 2014
EXAMPLE
a(2)=25 because there are 25 primes not greater than 541 (the 100th prime) that contain a 4's digit. Namely: 41, 43, 47, 149, 241, 347, 349, 401, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 541.
MATHEMATICA
cnt = 0; Table[Do[p = Prime[k]; If[MemberQ[IntegerDigits[p], 4], cnt++], {k, 10^(n - 1) + 1, 10^n}]; cnt, {n, 5}] (* T. D. Noe, Nov 13 2013 *)
CROSSREFS
Sequence in context: A197279 A061617 A078463 * A125413 A160084 A265967
KEYWORD
more,nonn,base
AUTHOR
Robert Price, Nov 13 2013
STATUS
approved

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Last modified June 13 15:33 EDT 2024. Contains 373389 sequences. (Running on oeis4.)