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A231796 Count of the first 10^n primes containing at least one 9's digit. 10
2, 31, 380, 4990, 54268, 581858, 6214940, 67420394, 703398930, 7316745778, 75645891943 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
a(n) ~ 10^n. - Charles R Greathouse IV, May 21 2014
EXAMPLE
a(2)=31 because there are 31 primes not greater than 541 (the 100th prime) that contain a 9's digit. Namely: 19, 29, 59, 79, 89, 97, 109, 139, 149, 179, 191, 193, 197, 199, 229, 239, 269, 293, 349, 359, 379, 389, 397, 409, 419, 439, 449, 479, 491, 499, 509.
MATHEMATICA
cnt = 0; Table[Do[p = Prime[k]; If[MemberQ[IntegerDigits[p], 9], cnt++], {k, 10^(n - 1) + 1, 10^n}]; cnt, {n, 5}] (* T. D. Noe, Nov 13 2013 *)
CROSSREFS
Sequence in context: A152278 A343415 A156151 * A218687 A071360 A108491
KEYWORD
more,nonn,base
AUTHOR
Robert Price, Nov 13 2013
STATUS
approved

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Last modified April 18 03:33 EDT 2024. Contains 371767 sequences. (Running on oeis4.)