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 A169965 Numbers whose decimal expansion contains only 0's and 2's. 14
 0, 2, 20, 22, 200, 202, 220, 222, 2000, 2002, 2020, 2022, 2200, 2202, 2220, 2222, 20000, 20002, 20020, 20022, 20200, 20202, 20220, 20222, 22000, 22002, 22020, 22022, 22200, 22202, 22220, 22222, 200000, 200002, 200020, 200022, 200200, 200202, 200220, 200222 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 FORMULA a(n+1) = Sum_{k>=0} A030308(n,k)*A093136(k+1). - Philippe Deléham, Oct 16 2011 a(n) = 2 * A007088(n-1). PROG (PARI) print1(0); for(d=1, 5, for(n=2^(d-1), 2^d-1, print1(", "); forstep(i=d-1, 0, -1, print1((n>>i)%2*2)))) \\ Charles R Greathouse IV, Nov 16 2011 (Haskell) a169965 n = a169965_list !! (n-1) a169965_list = map (* 2) a007088_list -- Reinhard Zumkeller, Jan 10 2012 CROSSREFS Cf. A007088, A014263, A169964, A169966, A169967. Cf. A078241, A204093, A204094, A204095, A097256. Sequence in context: A112405 A136885 A136909 * A202170 A136908 A196748 Adjacent sequences:  A169962 A169963 A169964 * A169966 A169967 A169968 KEYWORD nonn,base,easy AUTHOR N. J. A. Sloane, Aug 07 2010 STATUS approved

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Last modified December 1 20:42 EST 2020. Contains 338854 sequences. (Running on oeis4.)