%I A016029
%S A016029 1,1,2,5,10,19,38,77,154,307,614,1229,2458,4915,9830,19661,39322,
%T A016029 78643,157286,314573,629146,1258291,2516582,5033165,10066330,
%U A016029 20132659,40265318,80530637,161061274,322122547,644245094
%N A016029 a(1) = a(2) = 1, a(2n + 1) = 2*a(2n) and a(2n) = 2*a(2n - 1) + (-1)^n.
%C A016029 Row sums of Riordan array ((1+x^3)/(1-x^4),x/(1-x)); - Paul Barry (pbarry(AT)wit.ie), 
               Oct 08 2007
%F A016029 (1/10) {3*2^n + 3*(-1)^[n/2] - (-1)^[(n+1)/2]}. G.f.: x(1-x+x^2)/[(1-2x)(1+x^2)]. 
               - R. Stephan, Jan 12 2005
%F A016029 a(n)=2a(n-1)-a(n-2)+2a(n-3). Sequence is identical to its half second 
               differences from the second term. First differences: 0, 1, 3, 5, 
               9, 19, 39, ... = 0 before absolute values of A078066. Second differences: 
               1, 2, 2, 4, 10, 20, 38, ... = A100088. a(n)+a(n+2)=3*2^n, A007283;
               a(n)+a(n+6)=39*2^n. - Paul Curtz (bpcrtz(AT)free.fr), Dec 18 2007
%F A016029 a(n)=[1/5+(1/10)*I]*I^n+(3/5)*2^n+[1/5-(1/10)*I]*(-I)^n, with n>=0 and 
               I=sqrt(-1) - Paolo P. Lava (ppl(AT)spl.at), Jun 10 2008
%Y A016029 Sequence in context: A052944 A132736 A068035 this_sequence A018327 A000099 
               A039690
%Y A016029 Adjacent sequences: A016026 A016027 A016028 this_sequence A016030 A016031 
               A016032
%K A016029 nonn
%O A016029 1,3
%A A016029 Robert G. Wilson v (rgwv(AT)rgwv.com)