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A000773 Number of numbers == 0 (mod 3) in range 2^n to 2^n+1 with odd number of 1's in binary expansion. 2
0, 0, 0, 1, 1, 6, 8, 29, 45, 130, 220, 561, 1001, 2366, 4368, 9829, 18565, 40410, 77540, 164921, 320001, 669526, 1309528, 2707629, 5326685, 10919090, 21572460, 43942081, 87087001, 176565486, 350739488 (list; graph; refs; listen; history; internal format)
OFFSET

1,6

FORMULA

a(n) = (1/6)*{2^n - (-1)^n - 3^[(n+1)/2]}. G.f.: x^3 / [(1+x)(1-2x)(1-3x^2)]. - Ralf Stephan, Aug 08 2004

CROSSREFS

Cf. A000069.

Sequence in context: A024873 A066231 A007829 * A039720 A056097 A099431

Adjacent sequences:  A000770 A000771 A000772 * A000774 A000775 A000776

KEYWORD

easy,nonn

AUTHOR

Russ Cox (rsc(AT)swtch.com)

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Last modified February 15 10:06 EST 2012. Contains 205763 sequences.