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A062880 Zero together with numbers which can be written as a sum of distinct odd powers of 2. 13
0, 2, 8, 10, 32, 34, 40, 42, 128, 130, 136, 138, 160, 162, 168, 170, 512, 514, 520, 522, 544, 546, 552, 554, 640, 642, 648, 650, 672, 674, 680, 682, 2048, 2050, 2056, 2058, 2080, 2082, 2088, 2090, 2176, 2178, 2184, 2186, 2208, 2210, 2216, 2218, 2560, 2562 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Binary expansion of n does not contain 1-bits at even positions.

Integers whose base-4 representation consists of only 0s and 2s.

a(n)=2 A000695(n). Every nonnegative even number is a unique sum of the form a(k)+2a(l); moreover, this sequence is unique with such property. [Vladimir Shevelev, Nov 07 2008]

Also numbers such that the digital sum base 2 and the digital sum base 4 are in a ratio of 2:4. - Michel Marcus, Sep 23 2013

REFERENCES

D. H. Bailey, J. M. Borwein, R. E. Crandall, and C. Pomerance, On the binary expansions of algebraic numbers, J. Theor. Nombres Bordeaux, 16 (2004), 487-518.

S. Eigen, A. Hajian, and S. Kalikow, Ergodic transformations and sequences of integers, Israel J. Math. 75 (1991), 119-128; Math. Rev. 1147294 (93c:28014).

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

MAPLE

[seq(a(j), j=0..100)]; a := n -> add((floor(n/(2^i)) mod 2)*(2^((2*i)+1)), i=0..floor_log_2(n+1));

PROG

(Haskell)

a062880 n = a062880_list !! n

a062880_list = filter f [0..] where

   f 0 = True

   f x = (m == 0 || m == 2) && f x'  where (x', m) = divMod x 4

-- Reinhard Zumkeller, Nov 20 2012

CROSSREFS

Except for first term, n such that A063694(n) = 0. Binary expansion is given in A062033.

Interpreted as Zeckendorf expansion: A062879. A062880[n] = 2*A000695[n]

Central diagonal of arrays A163357 and A163359.

Sequence in context: A209449 A002510 A102943 * A066707 A107227 A188539

Adjacent sequences:  A062877 A062878 A062879 * A062881 A062882 A062883

KEYWORD

nonn,easy

AUTHOR

Antti Karttunen, Jun 26 2001

STATUS

approved

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Last modified September 15 00:00 EDT 2014. Contains 246771 sequences.