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A100588
Numerical value of the following string operation iterated n-1 times on the string "1": (1) Concatenate "0" to the left and to the right to the old string and initialize a new string. (2) Scan the old string from left to right. Whenever "00" occurs in the old string, write "0" to the new string; whenever "01" or "10" occurs in the old string, write "1" to the new string; whenever "11" occurs in the old string, write "10" to the new string.
0
1, 3, 13, 55, 885, 14175, 3628885, 928994815, 60882604217685, 3990002350010269695, 17136929604257253605596550485
OFFSET
0,2
EXAMPLE
Applying the operation to the initial string "1" gives us "11". Subsequent iterations give us "1101" and "110111". The numerical values corresponding to the binary strings "1," "11," "1101," and "110111" are, of course, 1, 3, 13 and 55.
CROSSREFS
Sequence in context: A151218 A151219 A006225 * A081952 A234645 A010920
KEYWORD
nonn
AUTHOR
George J. Schaeffer (gschaeff(AT)andrew.cmu.edu), Jan 02 2005
STATUS
approved