|
Search: id:A079968
|
|
|
| A079968 |
|
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={3}. |
|
+0
1
|
|
| 1, 1, 2, 4, 7, 14, 27, 51, 98, 187, 357, 683, 1305, 2494, 4767, 9110, 17411, 33276, 63596, 121544, 232293, 443954, 848478, 1621597, 3099169, 5923081, 11320094, 21634776, 41348026, 79023662, 151028714, 288643577, 551650823, 1054305916
(list; graph; listen)
|
|
|
OFFSET
|
0,3
|
|
|
COMMENT
|
Number of compositions (ordered partitions) of n into elements of the set {1,2,3,5,6}.
|
|
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.
|
|
FORMULA
|
Recurrence: a(n) = a(n-1)+a(n-2)+a(n-3)+a(n-5)+a(n-6) G.f.: -1/(x^6+x^5+x^3+x^2+x-1)
|
|
CROSSREFS
|
Cf. A002524-A002529, A072827, A072850-A072856, A079955-A080014.
Sequence in context: A027988 A005594 A123196 this_sequence A001631 A108758 A018085
Adjacent sequences: A079965 A079966 A079967 this_sequence A079969 A079970 A079971
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Vladimir Baltic (baltic(AT)matf.bg.ac.yu), Feb 19 2003
|
|
|
Search completed in 0.002 seconds
|
