OFFSET
0,4
REFERENCES
I. P. Goulden and D. M. Jackson, Combinatorial Enumeration, Wiley, N.Y., 1983,(Problem 2.4.13).
FORMULA
G.f.: -(x^4-x-1)*(x^4-x^2-1)*(x^4-x^3-1)/(x^16-x^15-x^14-3*x^12+3*x^11+x^10+2*x^9+6*x^8-x^7-3*x^6-2*x^5-5*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
Vladeta Jovovic, Jun 13 2001
STATUS
approved