%I #5 Jun 13 2015 00:51:52
%S 1,-2,-1,-4,-5,-6,-11,-8,-19,-10,-29,-12,-41,-14,-55,-16,-71,-18,-89,
%T -20,-109,-22,-131,-24,-155,-26,-181,-28,-209,-30,-239,-32,-271,-34,
%U -305,-36,-341,-38,-379,-40,-419,-42,-461,-44,-505,-46,-551,-48,-599,-50,-649,-52,-701,-54,-755,-56,-811,-58,-869,-60,-929
%N Diagonal sums of number a triangle related to the Pell numbers.
%C Diagonal sums of number triangle A110330.
%H <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (0,3,0,-3,0,1)
%F G.f.: (1-2x-4x^2+2x^3+x^4)/((1+x)^3(1-x)^3); a(n)=3a(n-2)-3a(n-4)+a(n-6); a(n)=-n(n+6)/8-(n^2-2n-8)(-1)^n/8.
%Y Cf. A028387 (bisection), A005843 (bisection).
%K easy,sign
%O 0,2
%A _Paul Barry_, Jul 20 2005
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