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A108693
Number of circular sequences of distinct positive integers between 1 and n such that the sum of any two consecutive elements is at least n+1.
0
1, 2, 4, 8, 15, 36, 80, 244, 677, 2530
OFFSET
1,2
EXAMPLE
For n=4 the circular sequences are 3, 4, 14, 23, 24, 34, 234 and 243, so a(4)=8.
CROSSREFS
Sequence in context: A145671 A316522 A317712 * A371351 A026096 A098864
KEYWORD
nonn
AUTHOR
Daniel Gulotta (dgulotta(AT)mit.edu), Jun 18 2005
STATUS
approved