OFFSET
1,2
LINKS
Muhammad Kholilurrohman, Table of n, a(n) for n = 1..300
P. Audibert, Mathematics for Informatics and Computer Science, Wiley, 2010, p. 824.
Muhammad Kholilurrohman and Shin-ichi Minato, An Efficient Algorithm for Enumerating Eulerian Paths, Hokkaido University, Division of Computer Science, TCS Technical Reports, TCS-TR-A-14-77, Oct. 2014.
FORMULA
Empirical g.f.: (x - 4*x^2)/(1 - 20*x + 16*x^2) and recurrence a(n) = 20*a(n-1) - 16*a(n-2). - Robert Israel, Dec 26 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Muhammad Kholilurrohman, Dec 23 2014
STATUS
approved