A252863 - OEIS

%I #16 Dec 28 2014 23:54:16

%S 1,16,304,5824,111616,2139136,40996864,785711104,15058272256,

%T 288594067456,5530948993024,106001474781184,2031534311735296,

%U 38934662638206976,746188703776374784,14300819473316184064,274077370205901684736,5252734292544974749696

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

%H Muhammad Kholilurrohman, <a href="/A252863/b252863.txt">Table of n, a(n) for n = 1..300</a>

%H P. Audibert, <a href="http://as.wiley.com/WileyCDA/WileyTitle/productCd-1848211961.html">Mathematics for Informatics and Computer Science</a>, Wiley, 2010, p. 824.

%H Muhammad Kholilurrohman and Shin-ichi Minato, <a href="http://www-alg.ist.hokudai.ac.jp/~thomas/TCSTR/tcstr_14_77/tcstr_14_77.pdf">An Efficient Algorithm for Enumerating Eulerian Paths</a>, Hokkaido University, Division of Computer Science, TCS Technical Reports, TCS-TR-A-14-77, Oct. 2014.

%F 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

%K nonn

%O 1,2

%A _Muhammad Kholilurrohman_, Dec 23 2014