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A193418 Expansion of x*(x^2+x-1)/(3*x^6-4*x^5+x^4-3*x^2+4*x-1). 1

%I

%S 1,3,8,23,69,206,616,1846,5537,16609,49824,149469,448405,1345212,

%T 4035632,12106892,36320673,108962015,326886040,980658115,2941974341,

%U 8825923018,26477769048,79433307138,238299921409,714899764221,2144699292656

%N Expansion of x*(x^2+x-1)/(3*x^6-4*x^5+x^4-3*x^2+4*x-1).

%C Conjecture: log(A005960-a(n)) ~ (log(2)*(2*n-11)).

%F a(n) = b(n+1,3)-b(n+1,4) with b(n,c) = sum(floor(3^m/2^c), m=1..n).

%F G.f.: x*(x^2+x-1) / (3*x^6-4*x^5+x^4-3*x^2+4*x-1).

%F a(n) = (9*3^n+4*n+1-(1+(-1)^n)*(1+4*i^n))/32, where i=sqrt(-1). - _Bruno Berselli_, Jul 30 2011

%Y Cf. A005960.

%K nonn

%O 1,2

%A _Yalcin Aktar_, Jul 26 2011

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Last modified November 14 10:04 EST 2019. Contains 329111 sequences. (Running on oeis4.)