A085977 Number of 3's in decimal expansion of prime(n).

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

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

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

Adjacent sequences: A085974 A085975 A085976 * A085978 A085979 A085980

Keyword

base,nonn

Author

Jason Earls, Jul 06 2003

Status

approved