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
KEYWORD
base,nonn
AUTHOR
Jason Earls, Jul 06 2003
STATUS
approved