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

Author

Jason Earls, Jul 06 2003

Keywords

• base
• nonn

Examples

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

Links

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

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.

Programs

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

Mathematica

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