OFFSET
0,8
COMMENTS
The sequence seems to consist of palindromic subsequences centered around each (2^k)-1 and 2^k (with end points near the terms of A000975), which is easily explained by symmetric pairing of binary expansion of n and its complement.
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..10922
MAPLE
a:= proc(n) local i, j, m, r, s; m, r, s:= n, 1, 1;
while m>0 do
for i from 0 while irem(m, 2, 'h')=0 do m:=h od;
for j from 0 while irem(m, 2, 'h')=1 do m:=h od;
r, s:= r*j, s*max(i, 1)
od; r-s
end:
seq(a(n), n=0..100); # Alois P. Heinz, Jul 11 2013
MATHEMATICA
a[n_] := With[{s = Split @ IntegerDigits[n, 2]}, Times @@ Length /@ Select[ s, First[#]==1&] - Times @@ Length /@ Select[s , First[#]==0&]]; Table[ a[n], {n, 0, 100}] (* Jean-François Alcover, Feb 28 2016 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Antti Karttunen, Jul 08 2013
STATUS
approved