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A213526 a(n) = 3*n AND n, where AND is the bitwise AND operator. 4
0, 1, 2, 1, 4, 5, 2, 5, 8, 9, 10, 1, 4, 5, 10, 13, 16, 17, 18, 17, 20, 21, 2, 5, 8, 9, 10, 17, 20, 21, 26, 29, 32, 33, 34, 33, 36, 37, 34, 37, 40, 41, 42, 1, 4, 5, 10, 13, 16, 17, 18, 17, 20, 21, 34, 37, 40, 41, 42, 49, 52, 53, 58, 61, 64, 65, 66, 65, 68 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Indices of 1's: A007583(n),

indices of 2's: A047849(n+1),

indices of 4's: A039301(n+2),

indices of 5's: A153643(n+3),

indices of 8's: A155701(n+2),

indices of 9's: A155701(n+2)+1 = A163868(n+2),

indices of 10's: A153643(n+4)+3^((n+1) mod 2),

indices of 13's: A039301(n+3)+3,

indices of 16's: A039301(n+3)+4,

indices of 17's: 17, 19, 27, 49, 51, 91, 177, 179, 347, 689, 691, 1371, 2737, 2739, 5467, 10929, 10931, 21851, 43697, 43699, 87387, 174769, 174771, 349531, 699057, 699059, 1398107, 2796209, 2796211, 5592411, 11184817, 11184819, 22369627, 44739249, 44739251, 89478491, ...

indices of 18's: A039301(n+3)+6,

n's such that a(n)<3: A005578, except the first term.

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..10000

MAPLE

a:= proc(n) local i, k, m, r;

      k, m, r:= n, 3*n, 0;

      for i from 0 while (m>0 or k>0) do

        r:= r +2^i* irem(m, 2, 'm') *irem(k, 2, 'k')

      od; r

    end:

seq(a(n), n=0..100);  # Alois P. Heinz, Jun 22 2012

MATHEMATICA

Table[BitAnd[n, 3*n], {n, 0, 68}] (* Arkadiusz Wesolowski, Jun 23 2012 *)

PROG

(Python)

for n in range(99):

    print 3*n & n,

(PARI) a(n)=bitand(n, 3*n) \\ Charles R Greathouse IV, Feb 05 2013

CROSSREFS

Sequence in context: A038574 A212713 A072014 * A210707 A078606 A065518

Adjacent sequences:  A213523 A213524 A213525 * A213527 A213528 A213529

KEYWORD

nonn,base,easy,look

AUTHOR

Alex Ratushnyak, Jun 13 2012

STATUS

approved

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Last modified October 20 04:05 EDT 2018. Contains 316378 sequences. (Running on oeis4.)