|
| |
|
|
A062203
|
|
Number of compositions of n such that two adjacent parts are not equal modulo 5.
|
|
3
|
|
|
|
1, 1, 1, 3, 4, 7, 14, 21, 38, 65, 110, 195, 329, 564, 975, 1675, 2885, 4950, 8503, 14627, 25158, 43255, 74325, 127775, 219662, 377662, 649313, 1116085, 1918690, 3298498, 5670521, 9748641, 16758575, 28809772, 49527786, 85143986, 146373609
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
0,4
|
|
|
REFERENCES
|
I. P. Goulden and D. M. Jackson, Combinatorial Enumeration, Wiley, N.Y., 1983, (Problem 2.4.13).
|
|
|
LINKS
|
|
|
|
FORMULA
|
G.f.: -(x^5-x-1)*(x^5-x^2-1)*(x^5-x^3-1)*(x^5-x^4-1) / (x^25 -x^24-x^23 -3*x^20+3*x^19 +3*x^18+x^17 +x^16+9*x^15 -5*x^14-5*x^13 -5*x^12-5*x^11 -9*x^10+2*x^9 +2*x^8+4*x^7 +4*x^6+7*x^5 +x^4+x^3-1). Generally, g.f. for the number of compositions of n such that two adjacent parts are not equal modulo p is 1/(1-Sum_{i=1..p} x^i/(1+x^i-x^p)).
|
|
|
CROSSREFS
|
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
|
|
|
STATUS
|
approved
|
| |
|
|
