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 A079967 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={4}. 0
 1, 1, 2, 4, 8, 15, 30, 58, 113, 220, 429, 835, 1627, 3169, 6173, 12024, 23422, 45623, 88869, 173107, 337194, 656817, 1279409, 2492150, 4854439, 9455922, 18419114, 35878442, 69887326, 136132954, 265172275, 516526919, 1006138588, 1959849178 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS Number of compositions (ordered partitions) of n into elements of the set {1,2,3,4,6}. Note that the number of compositions of n with parts in N which avoid the pattern 221 (see Heubach/Mansour) is not this sequence but A134044. 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..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. S. Heubach and T. Mansour, Enumeration of 3-letter patterns in combinations, arXiv:math/0603285 [math.CO], 2006. Index entries for linear recurrences with constant coefficients, signature (1,1,1,1,0,1). FORMULA a(n) = a(n-1)+a(n-2)+a(n-3)+a(n-4)+a(n-6). G.f.: -1/(x^6+x^4+x^3+x^2+x-1). CROSSREFS Cf. A002524-A002529, A072827, A072850-A072856, A079955-A080014. Sequence in context: A091865 A065494 A134044 * A192655 A018088 A374682 Adjacent sequences: A079964 A079965 A079966 * A079968 A079969 A079970 KEYWORD nonn,easy AUTHOR Vladimir Baltic, Feb 19 2003 STATUS approved

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Last modified August 13 07:44 EDT 2024. Contains 375113 sequences. (Running on oeis4.)