%I A104538
%S A104538 1,0,4,8,0,32,64,0,256,512,0,2048,4096,0,16384,32768,0,131072,262144,0,
               1048576,
%T A104538 2097152,0,8388608,16777216,0,67108864,134217728,0,536870912,1073741824,
               0,
%U A104538 4294967296,8589934592,0,34359738368,68719476736,0,274877906944,549755813888,
               0
%V A104538 1,0,-4,8,0,-32,64,0,-256,512,0,-2048,4096,0,-16384,32768,0,-131072,262144,
               0,-1048576,
%W A104538 2097152,0,-8388608,16777216,0,-67108864,134217728,0,-536870912,1073741824,
               0,
%X A104538 -4294967296,8589934592,0,-34359738368,68719476736,0,-274877906944,549755813888,
               0
%N A104538 Expansion of (1+2x)/(1+2x+4x^2).
%F A104538 a(n)=2^n*U(2n, 1/2), U(n, x) Chebyshev polynomial of second kind; a(n)=2^n*A057078(n).
%Y A104538 Sequence in context: A021212 A086468 A125507 this_sequence A120580 A013328 
               A143462
%Y A104538 Adjacent sequences: A104535 A104536 A104537 this_sequence A104539 A104540 
               A104541
%K A104538 easy,sign
%O A104538 0,3
%A A104538 Paul Barry (pbarry(AT)wit.ie), Mar 13 2005