|
%I #9 Jun 20 2017 01:35:16
%S 2,0,2,-1,2,-2,2,-3,2,-4,2,-5,2,-6,2,-7,2,-8,2,-9,2,-10,2,-11,2,-12,2,
%T -13,2,-14,2,-15,2,-16,2,-17,2,-18,2,-19,2,-20,2,-21,2,-22,2,-23,2,
%U -24,2,-25,2,-26,2,-27,2,-28,2,-29,2,-30,2,-31,2,-32,2,-33,2,-34,2,-35,2
%N a(2n+1)=2. a(2n)= 1-n.
%C A064680(n)+A022998(n-1) =c(n) = 2, 2, 10, 5, 18, 8, 26, 11,.. has differences c(2n)-c(2n-1) = -5*(n-1) = -A008587(n-1).
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (0,2,0,-1).
%F a(n) = n/4+3/2-(-1)^n*(n/4+1/2).
%F a(n)= +2*a(n-2) -a(n-4). G.f.: -x*(-2+2*x^2+x^3) / ( (x-1)^2*(1+x)^2 ).
%F a(n+1)-a(n) = (-1)^n*A008619(n+1).
%F a(n) = A064680(n)-A022998(n-1).
%Y Cf. A147657.
%K easy,sign
%O 1,1
%A _Paul Curtz_, Mar 05 2010
|
