login
A085976
Number of 2's in decimal expansion of prime(n).
11
1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0
OFFSET
1,48
LINKS
EXAMPLE
prime(4) = 7, so a(4)=0 and prime(2490) = 22229, so a(2490)=4.
MATHEMATICA
DigitCount[Prime[Range[110]], 10, 2] (* Harvey P. Dale, Jan 14 2014 *)
PROG
(Haskell)
a085976 = count2 0 . a000040 where
count2 c x | d == 2 = if x < 10 then c + 1 else count2 (c + 1) x'
| otherwise = if x < 10 then c else count2 c x'
where (x', d) = divMod x 10
-- Reinhard Zumkeller, Apr 08 2014
CROSSREFS
Cf. 0's A085974, 1's A085975, 3's A085977, 4's A085978, 5's A085979, 6's A085980, 7's A085981, 8's A085982, 9's A085983.
Sequence in context: A204429 A292560 A086137 * A171624 A032548 A030597
KEYWORD
base,nonn
AUTHOR
Jason Earls, Jul 06 2003
STATUS
approved