A190608 a(1)=a(2)=1; thereafter a(n) = 2*(a(ceiling(n/2))-a(floor(n/2))).

1, 1, 0, 0, -2, 0, 0, 0, -4, 0, 4, 0, 0, 0, 0, 0, -8, 0, 8, 0, 8, 0, -8, 0, 0, 0, 0, 0, 0, 0, 0, 0, -16, 0, 16, 0, 16, 0, -16, 0, 16, 0, -16, 0, -16, 0, 16, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -32, 0, 32, 0, 32, 0, -32, 0, 32, 0, -32, 0, -32, 0, 32, 0, 32, 0, -32, 0, -32, 0, 32, 0, -32, 0, 32, 0, 32

Offset

1,5

Links

Table of n, a(n) for n=1..93.

Maple

f:=proc(n) option remember;  local r; r:=2;
if n <= 2 then 1 else r*(f(ceil(n/2))-f(floor(n/2))); fi; end;

Crossrefs

Cf. A190609, A190610.

Sequence in context: A348616 A348613 A285182 * A011991 A234931 A129183

Adjacent sequences: A190605 A190606 A190607 * A190609 A190610 A190611

Keyword

sign

Author

N. J. A. Sloane, May 13 2011, based on a posting by Benoit CLOITRE to the Sequence Fans Mailing List, Apr 29 2011

Status

approved