

A103181


In decimal representation of n: replace all even digits with 0 and all odd digits with 1.


4



0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 10, 11, 10, 11, 10, 11, 10, 11, 10, 11, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 10, 11, 10, 11, 10, 11, 10, 11, 10, 11, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 10, 11, 10, 11, 10, 11, 10, 11, 10, 11, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 10, 11, 10, 11, 10, 11, 10, 11, 10, 11, 0, 1, 0, 1, 0, 1
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OFFSET

0,11


COMMENTS

a(A014263(n)) = 0.  Reinhard Zumkeller, Oct 04 2011


LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 0..9999


FORMULA

n=Sum(d(k)*10^k: 0<=d(k)<10) > a(n)=Sum((d(k) mod 2)*10^k).


EXAMPLE

199>'111': a(199)=111; 200>'000': a(200)=0;
299>'011': a(299)=11; 300>'100': a(300)=100.


PROG

(Haskell)
import Data.List (unfoldr); import Data.Tuple (swap)
a103181_list = map a103181 [0..]
a103181 n = foldl f 0 $ reverse $ unfoldr g n where
f v d = 10 * v + mod d 2
g x = if x == 0 then Nothing else Just $ swap $ divMod x 10
 Reinhard Zumkeller, Oct 04 2011
(PARI) a(n)=subst(Pol(apply(k>k%2, digits(n))), 'x, 10) \\ Charles R Greathouse IV, Jul 16 2013


CROSSREFS

Cf. A000035.
Sequence in context: A004451 A004499 A020509 * A100813 A085209 A085217
Adjacent sequences: A103178 A103179 A103180 * A103182 A103183 A103184


KEYWORD

nonn,base,easy


AUTHOR

Reinhard Zumkeller, Mar 18 2005


STATUS

approved



