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A159786
Total area of all squares and rectangles after n-th stage in the toothpick structure of A139250, assuming the toothpicks have length 2.
12
0, 0, 0, 4, 8, 8, 12, 32, 48, 48, 52, 64, 72, 76, 104, 176, 224, 224, 228, 240, 248, 252, 280, 336, 368, 372, 392, 424, 444, 480, 608, 864, 960, 960, 964, 976, 984, 988, 1016, 1072, 1104, 1108, 1128, 1160, 1180, 1216, 1344, 1536, 1632, 1636, 1656
OFFSET
0,4
COMMENTS
Note that if n > 1 is a power of 2 then a(n) = n^2 - 2n.
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.]
FORMULA
a(2^k) = A211012(k). - Omar E. Pol, Sep 25 2012
CROSSREFS
KEYWORD
nonn
AUTHOR
Omar E. Pol, Apr 28 2009
EXTENSIONS
More terms from Omar E. Pol, Sep 25 2012
STATUS
approved