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 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 (list; graph; refs; listen; history; text; internal format)
 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

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Last modified November 26 03:33 EST 2022. Contains 358353 sequences. (Running on oeis4.)