%I A098335
%S A098335 1,2,2,4,26,68,76,184,1222,3308,3772,9656,64676,177448,203992,536176,
%T A098335 3607622,9968972,11510636,30723416,207302156,575382392,666187432,
%U A098335 1796105744,12142184476,33803271032
%V A098335 1,2,2,-4,-26,-68,-76,184,1222,3308,3772,-9656,-64676,-177448,-203992,
               536176,3607622,
%W A098335 9968972,11510636,-30723416,-207302156,-575382392,-666187432,1796105744,
               12142184476,
%X A098335 33803271032
%N A098335 Expansion of 1/sqrt(1-4x+8x^2).
%C A098335 Central coefficients of (1+2x-x^2)^n. Binomial transform of A098331.
%D A098335 Tony D. Noe, On the Divisibility of Generalized Central Trinomial Coefficients, 
               Journal of Integer Sequences, Vol. 9 (2006), Article 06.2.7.
%F A098335 E.g.f. : exp(2x)BesselI(0, 2*I*x), I=sqrt(-1); a(n)=sum{k=0..floor(n/
               2), binomial(n, k)binomial(n-k, k)2^n(-4)^(-k)}.
%F A098335 a(n)=sum{k=0..floor(n/2), binomial(n, k)binomial(2(n-k), k)(-2)^k} - 
               Paul Barry (pbarry(AT)wit.ie), Sep 08 2004
%Y A098335 Sequence in context: A009541 A006829 A154594 this_sequence A049147 A067068 
               A032334
%Y A098335 Adjacent sequences: A098332 A098333 A098334 this_sequence A098336 A098337 
               A098338
%K A098335 easy,sign
%O A098335 0,2
%A A098335 Paul Barry (pbarry(AT)wit.ie), Sep 03 2004