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A079968
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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={3}.
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1
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1, 1, 2, 4, 7, 14, 27, 51, 98, 187, 357, 683, 1305, 2494, 4767, 9110, 17411, 33276, 63596, 121544, 232293, 443954, 848478, 1621597, 3099169, 5923081, 11320094, 21634776, 41348026, 79023662, 151028714, 288643577, 551650823, 1054305916
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OFFSET
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0,3
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COMMENTS
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Number of compositions (ordered partitions) of n into elements of the set {1,2,3,5,6}.
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REFERENCES
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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.
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LINKS
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Table of n, a(n) for n=0..33.
Vladimir Baltic, On the number of certain types of strongly restricted permutations, Applicable Analysis and Discrete Mathematics Vol. 4, No 1 (2010), 119-135
Index to sequences with linear recurrences with constant coefficients, signature (1,1,1,0,1,1).
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FORMULA
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a(n) = a(n-1)+a(n-2)+a(n-3)+a(n-5)+a(n-6) G.f.: -1/(x^6+x^5+x^3+x^2+x-1)
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CROSSREFS
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Cf. A002524-A002529, A072827, A072850-A072856, A079955-A080014.
Sequence in context: A217933 A005594 A123196 * A001631 A108758 A018085
Adjacent sequences: A079965 A079966 A079967 * A079969 A079970 A079971
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KEYWORD
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nonn,easy
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AUTHOR
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Vladimir Baltic, Feb 19 2003
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STATUS
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approved
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