%I A026244
%S A026244 1,10,136,2080,32896,524800,8390656,134225920,2147516416,34359869440,
%T A026244 549756338176,8796095119360,140737496743936,2251799847239680,36028797153181696,
%U A026244 576460752840294400,9223372039002259456,147573952598266347520,2361183241469182345216
%N A026244 4^n*(4^n+1)/2.
%F A026244 With interpolated zeros 0, 1, 0, 10, ... has a(n)=(4^n-(-4)^n+2*2^n-2*(-2)^n)/
               16 and counts walks of length n between adjacent vertices of the 
               4-cube. G.f.: (1-10x)/((1-4x)(1-16x)); - Paul Barry (pbarry(AT)wit.ie), 
               Mar 11 2004
%F A026244 a(n)= sum{k=0..n, 9k*binomial(2n,2k)}= sum{k=0..n, 9^k*A086645(n,k)}; 
               a(n)=8^n*T(n,5/4) where T is the Chebyshev polynomial of first kind 
               ; e.g.f.: exp(10x)cosh(6x) . [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), 
               Sep 08 2009]
%p A026244 seq(binomial(-4^n, 2), n=0..18); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), 
               Feb 22 2008
%Y A026244 Sequence in context: A128862 A129803 A065024 this_sequence A096619 A003377 
               A065593
%Y A026244 Adjacent sequences: A026241 A026242 A026243 this_sequence A026245 A026246 
               A026247
%K A026244 nonn
%O A026244 0,2
%A A026244 N. J. A. Sloane (njas(AT)research.att.com).