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A085977
Number of 3's in decimal expansion of prime(n).
10
0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 2, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1, 1, 2, 1, 2, 2, 1, 1, 2, 1, 1, 2, 1, 2, 1, 1, 0, 0, 0, 0, 1, 2, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0
OFFSET
1,51
LINKS
EXAMPLE
prime(2) = 3, so a(2)=1 and prime(345) = 2333, so a(345)=3.
MATHEMATICA
DigitCount[Prime[Range[110]], 10, 3] (* Harvey P. Dale, Aug 05 2019 *)
PROG
(Haskell)
a085977 = count3 0 . a000040 where
count3 c x | d == 3 = if x < 10 then c + 1 else count3 (c + 1) x'
| otherwise = if x < 10 then c else count3 c x'
where (x', d) = divMod x 10
-- Reinhard Zumkeller, Apr 08 2014
CROSSREFS
Cf. 0's A085974, 1's A085975, 2's A085976, 4's A085978, 5's A085979, 6's A085980, 7's A085981, 8's A085982, 9's A085983.
Sequence in context: A077655 A117886 A145723 * A375482 A288424 A127325
KEYWORD
base,nonn
AUTHOR
Jason Earls, Jul 06 2003
STATUS
approved