|
|
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
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,more
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|