acwacw at gmail.com (Allan Wechsler) writes: > > At each step we toggle one bit ... > 0,1,0,2,3,2,0,4,5,4,6,7,6,4,0,8,9,8,10,11,10,8,12,13,12,14,15,14,12,8,0,... The bit which toggles looks like A182105. If true, it'd make you partial-XORs of A182105. (And then A215020 the bit position number.)