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A168115
a(n) = A139560(n+1)/2.
0
1, 1, 1, 2, 2, 1, 1, 2, 2, 2, 4, 6, 4, 1, 1, 2, 2, 2, 4, 6, 4, 2, 4, 6, 6, 8, 14, 16, 8, 1, 1, 2, 2, 2, 4, 6, 4, 2, 4, 6, 6, 8, 14, 16, 8, 2, 4, 6, 6, 8, 14, 16, 10, 8, 14, 18, 20, 30, 44, 40, 16, 1, 1, 2, 2, 2, 4, 6, 4, 2, 4, 6, 6, 8, 14, 16
OFFSET
1,4
LINKS
David Applegate, Omar E. Pol and N. J. A. Sloane, The Toothpick Sequence and Other Sequences from Cellular Automata, Congressus Numerantium, Vol. 206 (2010), 157-191. [There is a typo in Theorem 6: (13) should read u(n) = 4.3^(wt(n-1)-1) for n >= 2.]
CROSSREFS
KEYWORD
nonn
AUTHOR
Omar E. Pol, Dec 09 2009
EXTENSIONS
Terms after a(27) from Nathaniel Johnston, Mar 29 2011
STATUS
approved