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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
FORMULA
a(n+1) = Sum_{k>=0} A030308(n,k)*A093136(k+1). - Philippe Deléham, Oct 16 2011
a(n) = 2 * A007088(n-1).
MATHEMATICA
Map[FromDigits, Tuples[{0, 2}, 6]] (* Paolo Xausa, Oct 30 2023 *)
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
Sequence in context: A136885 A359611 A136909 * A202170 A136908 A196748
KEYWORD
nonn,base,easy
AUTHOR
N. J. A. Sloane, Aug 07 2010
STATUS
approved

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Last modified May 21 00:14 EDT 2024. Contains 372720 sequences. (Running on oeis4.)