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A080008 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}. 0
1, 0, 0, 1, 2, 2, 3, 5, 11, 15, 24, 40, 68, 110, 177, 290, 480, 783, 1278, 2090, 3427, 5609, 9171, 15005, 24564, 40200, 65776, 107628, 176137, 288244, 471676, 771845, 1263074, 2066938, 3382367, 5534941, 9057495, 14821891, 24254820, 39691008 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

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

Table of n, a(n) for n=0..39.

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 (0,1,1,2,2,0,-1,0,-1,-1).

FORMULA

Recurrence: a(n) = a(n-2)+a(n-3)+2*a(n-4)+2*a(n-5)-a(n-7)-a(n-9)-a(n-10).

G.f.: -(x^5+x^2-1)/((x^9+x^6-x^5-x^4-x^3-x+1)*(x+1))

CROSSREFS

Cf. A002524-A002529, A072827, A072850-A072856, A079955-A080014.

Sequence in context: A127180 A249241 A089540 * A058697 A030427 A049907

Adjacent sequences:  A080005 A080006 A080007 * A080009 A080010 A080011

KEYWORD

nonn

AUTHOR

Vladimir Baltic, Feb 10 2003

STATUS

approved

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Last modified November 1 05:10 EDT 2014. Contains 248888 sequences.