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A001415 Number of ways of folding a 2 X n strip of stamps.
(Formerly M1891 N0745)
0
1, 2, 8, 60, 320, 1980, 10512, 60788, 320896, 1787904, 9381840, 51081844, 266680992, 1429703548, 7432424160, 39409195740, 204150606976, 1073644675448, 5545305620064 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
a(n), called G(n,2), is known to be divisible by 4n for n >= 2. - Fred Lunnon, Dec 08 2013
REFERENCES
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
R. Dickau, Map Folding
R. Dickau, Folding a 2xn Sheet of Labeled Stamps, Wolfram Demonstrations Project
W. F. Lunnon, Multi-dimensional map-folding, Computer Journal 14 1971 75-80.
Eric Weisstein's World of Mathematics, Map Folding
CROSSREFS
Sequence in context: A295502 A196076 A027278 * A305730 A364077 A053871
KEYWORD
nonn,more
AUTHOR
EXTENSIONS
a(12)-a(18) from Fred Lunnon, Dec 08 2013
STATUS
approved

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Last modified March 19 01:22 EDT 2024. Contains 370952 sequences. (Running on oeis4.)