

A252863


Number of Eulerian paths in a lattice graph bounded by the four equations x+y=1, x+y=2n, xy=2, and xy=2.


1



1, 16, 304, 5824, 111616, 2139136, 40996864, 785711104, 15058272256, 288594067456, 5530948993024, 106001474781184, 2031534311735296, 38934662638206976, 746188703776374784, 14300819473316184064, 274077370205901684736, 5252734292544974749696
(list;
graph;
refs;
listen;
history;
text;
internal format)



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 Shinichi Minato, An Efficient Algorithm for Enumerating Eulerian Paths, Hokkaido University, Division of Computer Science, TCS Technical Reports, TCSTRA1477, Oct. 2014.


FORMULA

Empirical g.f.: (x  4*x^2)/(1  20*x + 16*x^2) and recurrence a(n) = 20*a(n1)  16*a(n2).  Robert Israel, Dec 26 2014


CROSSREFS

Sequence in context: A300264 A253302 A227678 * A039746 A232834 A232841
Adjacent sequences: A252860 A252861 A252862 * A252864 A252865 A252866


KEYWORD

nonn


AUTHOR

Muhammad Kholilurrohman, Dec 23 2014


STATUS

approved



