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A211976
First differences of the E-toothpick sequence A211964.
3
1, 1, 1, 2, 1, 2, 2, 2, 3, 2, 3, 4, 1, 2, 2, 3, 5, 3, 7, 4, 5, 7, 4, 6, 7, 2, 4, 4, 5, 8, 6, 11, 8, 8, 9, 6, 7, 8, 8, 8, 5, 6, 10, 7, 11, 11, 9, 9, 12, 9, 14, 9, 10, 14, 11, 14, 10, 9, 9, 11, 16, 16, 13, 12, 11, 14, 14, 16, 17, 10, 10, 14
OFFSET
1,4
COMMENTS
Number of E-toothpicks added at n-th stage to the triangular structure of A211964.
FORMULA
a(n) = ((A161331(n+1)/6) + 1)/2.
CROSSREFS
KEYWORD
nonn
AUTHOR
Omar E. Pol, Dec 15 2012
STATUS
approved