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A079988 Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=3, r=3, I={0,1,2}. 0
1, 0, 0, 0, 1, 3, 3, 3, 6, 10, 29, 39, 61, 101, 179, 335, 566, 928, 1575, 2705, 4747, 8117, 13782, 23464, 40216, 69209, 118650, 202712, 346508, 593180, 1016874, 1741871, 2981190, 5101520, 8733466, 14956519, 25611753, 43847283, 75061015, 128505176 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,6

COMMENTS

Also, number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=3, r=3, I={-2,-1,0}.

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

FORMULA

a(n) = a(n-2) +a(n-3) +a(n-4) +4*a(n-5) +4*a(n-6) -a(n-7) -3*a(n-8) -2*a(n-9) +a(n-10) -4*a(n-11) -3*a(n-12) +a(n-13) +4*a(n-14) -a(n-16) +a(n-17) +a(n-18) -a(n-20) .

G.f.: -(x^14-x^12 -x^11+x^9 -2*x^8+2*x^6 +x^5+x^3 +x^2-1)/( x^20 -x^18 -x^17 +x^16 -4*x^14 -x^13 +3*x^12 +4*x^11 -x^10 +2*x^9 +3*x^8 +x^7 -4*x^6 -4*x^5 -x^4 -x^3 -x^2+1).

CROSSREFS

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

Sequence in context: A132972 A113920 A081848 * A212091 A061021 A126608

Adjacent sequences:  A079985 A079986 A079987 * A079989 A079990 A079991

KEYWORD

nonn

AUTHOR

Vladimir Baltic, Feb 17 2003

STATUS

approved

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Last modified September 24 04:42 EDT 2020. Contains 337317 sequences. (Running on oeis4.)