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A084471
Change 0 to 00 in binary representation of n.
10
1, 4, 3, 16, 9, 12, 7, 64, 33, 36, 19, 48, 25, 28, 15, 256, 129, 132, 67, 144, 73, 76, 39, 192, 97, 100, 51, 112, 57, 60, 31, 1024, 513, 516, 259, 528, 265, 268, 135, 576, 289, 292, 147, 304, 153, 156, 79, 768, 385, 388, 195, 400, 201, 204, 103, 448, 225
OFFSET
1,2
COMMENTS
a(n) = n iff n = 2^k - 1, k>0.
A023416(a(n))=A023416(n)*2; A000120(a(n))=A000120(n);
LINKS
FORMULA
a(1)=1, a(2*k+1)=2*a(k)+1, a(2*k)=4*a(k).
MAPLE
a:= n-> Bits[Join](subs(0=[0$2][], Bits[Split](n))):
seq(a(n), n=1..60); # Alois P. Heinz, Jan 15 2021
MATHEMATICA
f[n_] := FromDigits[Flatten[IntegerDigits[n, 2] /. {0 -> {0, 0}}], 2]; Array[f, 60] (* Robert G. Wilson v, Dec 10 2009 *)
PROG
(Haskell)
a084471 1 = 1
a084471 x = 2 * (2 - d) * a084471 x' + d where (x', d) = divMod x 2
-- Reinhard Zumkeller, Jul 16 2012
CROSSREFS
Cf. A084472(n)=A007088(a(n)), A084473, A038573.
Ordered terms are in A060142.
Column k=2 of A340666.
Cf. A088698, A175047. - Robert G. Wilson v, Dec 10 2009
Sequence in context: A062776 A269512 A270128 * A285122 A277773 A277800
KEYWORD
nonn,look,base
AUTHOR
Reinhard Zumkeller, May 27 2003
STATUS
approved