

A133680


a(n)=8*a(n1)+72*a(n2) for n>=3, a(0)=1, a(1)=8, a(2)=128 .


2



1, 8, 128, 1600, 22016, 291328, 3915776, 52301824, 700350464, 9368535040, 125373513728, 1677522632704, 22447074050048, 300358221955072, 4019055107244032, 53778232838717440, 719597830431309824
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OFFSET

0,2


LINKS



FORMULA

G.f.: (18*x^2)/(18*x72*x^2) . a(n) = Sum_{k, 0<=k<=n}A122950(n,k)*8^k .
a(n)=4*[4+2*sqrt(22)]^(n1)+4*[42*sqrt(22)]^(n1)+(12/11)*[4+2*sqrt(22)]^(n1)*sqrt(22)(12/11)*[42 *sqrt(22)]^(n1)*sqrt(22)+(1/9)*[C(2*n,n) mod 2], with n>=0 [From Paolo P. Lava, Aug 28 2008]


MATHEMATICA

LinearRecurrence[{8, 72}, {1, 8, 128}, 20] (* Harvey P. Dale, Sep 15 2015 *)


CROSSREFS



KEYWORD

easy,nonn


AUTHOR



STATUS

approved



