OFFSET
0,1
COMMENTS
REFERENCES
Venkat Murali, On the enumeration of fuzzy subsets of an (n+5)-element set X_(n+5) of specification n^1 4^1 1, Rhodes University JRC-Abstract-Report, In Preparation, 15 pages 2005.
LINKS
Venkat Murali, Home page.
Index entries for linear recurrences with constant coefficients, signature (13,-72,220,-400,432,-256,64).
FORMULA
a(n) = (2^(n+1))*(1/24)*(n^5 + 36*n^4 + 431*n^3 + 2088*n^2 + 3972*n + 2304) - 1,
G.f.: (320*x^5-1360*x^4+2400*x^3-2180*x^2+1012*x-191) / ((x-1)*(2*x-1)^6). [Colin Barker, Dec 10 2012]
EXAMPLE
a(3) = (2^(3+1))*(1/24)*(3^5 + 36 * 3^4 + 431 * 3^3 + 2088 * 3^2 + 3972 * 3 + 2304) - 1 = 31871. This is the number of chains in the power set lattice (which is also the number of fuzzy subsets) of X_(n+5).
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Venkat Murali (v.murali(AT)ru.ac.za), Jun 01 2005
STATUS
approved