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A080002
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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=2, r=3, I={-1,0,1}.
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0
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1, 0, 0, 0, 1, 1, 0, 0, 1, 3, 1, 1, 1, 6, 6, 4, 5, 10, 20, 16, 20, 25, 50, 60, 66, 85, 125, 190, 216, 281, 365, 545, 701, 883, 1156, 1576, 2176, 2761, 3636, 4784, 6560, 8620, 11265, 14856, 19840, 26600, 34825, 46045, 60856, 81420, 107625, 142055, 187881, 249461
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,10
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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.
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FORMULA
| Recurrence: a(n) = a(n-2)+a(n-4)+2*a(n-5)-a(n-6)-a(n-7)-a(n-10) G.f.: -(x^5+x^2-1)/(x^10+x^7+x^6-2*x^5-x^4-x^2+1)
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MATHEMATICA
| LinearRecurrence[{0, 1, 0, 1, 2, -1, -1, 0, 0, -1}, {1, 0, 0, 0, 1, 1, 0, 0, 1, 3}, 60] (* From Harvey P. Dale, Dec 14 2011 *)
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CROSSREFS
| Cf. A002524-A002529, A072827, A072850-A072856, A079955-A080014.
Sequence in context: A180051 A160752 A186024 * A058057 A124372 A126470
Adjacent sequences: A079999 A080000 A080001 * A080003 A080004 A080005
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KEYWORD
| nonn
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AUTHOR
| Vladimir Baltic (baltic(AT)matf.bg.ac.yu), Feb 10 2003
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