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A127195 Number of subsets of {1,2,...,n} which contain no three consecutive odd numbers. 0
2, 4, 8, 16, 28, 56, 104, 208, 384, 768, 1408, 2816, 5184, 10368, 19072, 38144, 70144, 140288, 258048, 516096, 949248, 1898496, 3491840, 6983680, 12845056, 25690112, 47251456, 94502912, 173817856, 347635712, 639401984, 1278803968 (list; graph; refs; listen; history; internal format)
OFFSET

0,1

FORMULA

a(n) = A000073(floor((n+1)/2)-3) * 2^(floor(n/2))

CROSSREFS

Sequence in context: A112128 A172020 A054189 * A177269 A018726 A049884

Adjacent sequences:  A127192 A127193 A127194 * A127196 A127197 A127198

KEYWORD

easy,nonn

AUTHOR

Fung Cheok Yin (cheokyin_restart(AT)yahoo.com.hk), Mar 27 2007

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Last modified February 17 10:05 EST 2012. Contains 206009 sequences.