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A079975 Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=1, r=4, I={3}. 1
1, 1, 2, 4, 7, 14, 26, 49, 93, 175, 331, 625, 1180, 2229, 4209, 7949, 15012, 28350, 53540, 101111, 190950, 360613, 681024, 1286127, 2428875, 4586976, 8662591, 16359466, 30895160, 58346092, 110187694, 208091537, 392984789, 742159180 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
COMMENTS
Number of compositions (ordered partitions) of n into elements of the set {1,2,3,5}.
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
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
Recurrence: a(n) = a(n-1)+a(n-2)+a(n-3)+a(n-5).
G.f.: -1/(x^5+x^3+x^2+x-1).
CROSSREFS
Sequence in context: A054191 A347761 A257792 * A253511 A076739 A017996
KEYWORD
nonn,easy,changed
AUTHOR
Vladimir Baltic, Feb 17 2003
STATUS
approved

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Last modified April 24 20:06 EDT 2024. Contains 371963 sequences. (Running on oeis4.)