A085975 Number of 1's in decimal expansion of prime(n).

0, 0, 0, 0, 2, 1, 1, 1, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 2, 1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 2, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 2, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1

Offset

1,5

Links

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

Example

prime(5) = 11, so a(5)=2 and prime(1242) = 10111, so a(1242)=4.

Mathematica

DigitCount[Prime[Range[100]], 10, 1] (* Paolo Xausa, Oct 30 2023 *)

Prog

(Haskell)
a085975 = count1 0 . a000040 where
   count1 c x | d == 1    = if x < 10 then c + 1 else count1 (c + 1) x'
              | otherwise = if x < 10 then c else count1 c x'
              where (x', d) = divMod x 10
-- Reinhard Zumkeller, Apr 08 2014

Crossrefs

Cf. 0's A085974, 2's A085976, 3's A085977, 4's A085978, 5's A085979, 6's A085980, 7's A085981, 8's A085982, 9's A085983.

Sequence in context: A077267 A134022 A262097 * A277778 A255319 A214088

Adjacent sequences: A085972 A085973 A085974 * A085976 A085977 A085978

Keyword

base,nonn

Author

Jason Earls, Jul 06 2003

Status

approved