Hankel transform of g.f. 1/sqrt(1+4x^2).

Terms

a(0) =1a(1) =-2a(2) =-4a(3) =8a(4) =16a(5) =-32a(6) =-64a(7) =128a(8) =256a(9) =-512a(10) =-1024a(11) =2048a(12) =4096a(13) =-8192a(14) =-16384a(15) =32768a(16) =65536a(17) =-131072a(18) =-262144a(19) =524288a(20) =1048576a(21) =-2097152a(22) =-4194304a(23) =8388608a(24) =16777216a(25) =-33554432a(26) =-67108864a(27) =134217728a(28) =268435456a(29) =-536870912