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First column of triangle A103910.
1

%I #3 Apr 30 2014 01:31:16

%S 1,-1,0,1,-1,-6,35,181,-6056,-3741,5880885,-149991434,-32148902071,

%T 4867910308359,891980177502800,-740991835820243639,

%U -53134975005564905081,626000780698404972023994

%N First column of triangle A103910.

%C The sign of a(n) appears to follow a 7-periodic pattern.

%F Recurrence: a(n) = -Sum[i=1..n-1, a(i)*A010048(n-1, i-1) ] (conjectured).

%K sign

%O 1,6

%A _Ralf Stephan_, Feb 24 2005