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Search: id:A079956
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| A079956 |
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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={0,1,4}. |
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+0
1
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| 1, 0, 0, 1, 1, 0, 2, 2, 1, 3, 5, 3, 6, 10, 9, 12, 21, 22, 27, 43, 52, 61, 91, 117, 140, 195, 260, 318, 426, 572, 718, 939, 1258, 1608, 2083, 2769, 3584, 4630, 6110, 7961, 10297, 13509, 17655, 22888, 29916, 39125, 50840, 66313, 86696, 112853, 147069, 192134
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OFFSET
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0,7
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COMMENT
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Number of compositions (ordered partitions) of n into elements of the set {3,4,6}.
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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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FORMULA
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Recurrence: a(n) = a(n-3)+a(n-4)+a(n-6) G.f.: -1/(x^6+x^4+x^3-1)
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CROSSREFS
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Cf. A002524-A002529, A072827, A072850-A072856, A079955-A080014.
Sequence in context: A139375 A106198 A054336 this_sequence A140717 A026300 A099514
Adjacent sequences: A079953 A079954 A079955 this_sequence A079957 A079958 A079959
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KEYWORD
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nonn
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AUTHOR
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Vladimir Baltic (baltic(AT)matf.bg.ac.yu), Feb 19 2003
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