A071413 a(n) = if n=0 then 0 else a(floor(n/2))+n*(-1)^(n mod 2).

0, -1, 1, -4, 5, -4, 2, -11, 13, -4, 6, -15, 14, -11, 3, -26, 29, -4, 14, -23, 26, -15, 7, -38, 38, -11, 15, -38, 31, -26, 4, -57, 61, -4, 30, -39, 50, -23, 15, -62, 66, -15, 27, -58, 51, -38, 8, -85, 86, -11, 39, -62, 67, -38, 16, -93, 87, -26, 32, -85, 64, -57, 5