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 A112403 G.f.: (1-16*x+28*x^2+56*x^3-140*x^4+56*x^5+28*x^6-16*x^7+x^8)/(x^2-x+1)^8. 0

%I #6 Jun 24 2014 01:08:37

%S 1,-8,-72,-120,330,1584,1716,-3432,-12870,-11440,19448,63648,50388,

%T -77520,-232560,-170544,245157,692208,480700,-657800,-1776060,

%U -1184040,1560780,4071600,2629575,-3365856,-8544096,-5379616

%N G.f.: (1-16*x+28*x^2+56*x^3-140*x^4+56*x^5+28*x^6-16*x^7+x^8)/(x^2-x+1)^8.

%C Sequence is interesting because the initial terms seem to have many small factors.

%F a(n) = 2 cos(pi (n+1)/3) binomial(n+7,7). Note that 2 cos(pi (n+1)/3) is always 1, -1, 2, or -2, so this formula explains the small factors. - _Dean Hickerson_, Feb 06 2006

%K sign

%O 0,2

%A _Creighton Dement_, Dec 06 2005

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Last modified June 8 18:04 EDT 2023. Contains 363165 sequences. (Running on oeis4.)