A103181 In decimal representation of n: replace all even digits with 0 and all odd digits with 1.

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

Offset

0,11

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).

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

Example

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

Mathematica

Table[FromDigits[If[EvenQ[#], 0, 1]&/@IntegerDigits[n]], {n, 0, 90}] (* Harvey P. Dale, Nov 08 2022 *)

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
(Python)
def A103181(n): return int(''.join(str(int(d) % 2) for d in str(n))) # Chai Wah Wu, Apr 09 2022

Crossrefs

Cf. A000035, A014263.

Sequence in context: A352390 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