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A171475 a(n) = 6*a(n-1)-8*a(n-2) for n > 2; a(0) = 1, a(1) = 6, a(2) = 27. 1

%I

%S 1,6,27,114,468,1896,7632,30624,122688,491136,1965312,7862784,

%T 31454208,125822976,503304192,2013241344,8053014528,32212156416,

%U 128848822272,515395682304,2061583515648,8246335635456,32985345687552

%N a(n) = 6*a(n-1)-8*a(n-2) for n > 2; a(0) = 1, a(1) = 6, a(2) = 27.

%C Binomial transform of A037480; second binomial transform of A133600.

%C First differences of A080960.

%H Vincenzo Librandi, <a href="/A171475/b171475.txt">Table of n, a(n) for n = 0..500</a>

%F a(n) = 3*(5*4^n-2*2^n)/8 for n > 0.

%F G.f.: (1-x)*(1+x)/((1-2*x)*(1-4*x)).

%o (PARI) {m=21; v=concat([1, 6, 27], vector(m-3)); for(n=4, m, v[n]=6*v[n-1]-8*v[n-2]); v}

%Y Cf. A037480 ((5*3^n+(-1)^n-6)/8), A133600 (row sums of triangle A133599), A080960 (third binomial transform of A010685).

%K nonn,easy

%O 0,2

%A _Klaus Brockhaus_, Dec 09 2009

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Last modified August 21 18:26 EDT 2019. Contains 326168 sequences. (Running on oeis4.)