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A079957
Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=1, r=5, I={0,1,3}.
3
1, 0, 0, 1, 0, 1, 2, 0, 2, 3, 1, 5, 5, 3, 10, 9, 9, 20, 17, 22, 39, 35, 51, 76, 74, 112, 150, 160, 239, 300, 346, 501, 610, 745, 1040, 1256, 1592, 2151, 2611, 3377, 4447, 5459, 7120, 9209, 11447, 14944, 19115, 24026, 31273, 39771, 50417, 65332, 82912, 105716
OFFSET
0,7
COMMENTS
Number of compositions (ordered partitions) of n into elements of the set {3,5,6}.
REFERENCES
D. H. Lehmer, Permutations with strongly restricted displacements. Combinatorial theory and its applications, II (Proc. Colloq., Balatonfured, 1969), pp. 755-770. North-Holland, Amsterdam, 1970.
LINKS
Vladimir Baltic, On the number of certain types of strongly restricted permutations, Applicable Analysis and Discrete Mathematics Vol. 4, No 1 (2010), 119-135.
FORMULA
a(n) = a(n-3)+a(n-5)+a(n-6).
G.f.: -1/(x^6+x^5+x^3-1).
KEYWORD
nonn,easy
AUTHOR
Vladimir Baltic, Feb 19 2003
STATUS
approved