A050821 Even numbers in the sequence generated by a(n)=|a(n-1)+2a(n-2)-n|.

0, 2, 0, 6, 0, 2, 8, 6, 8, 10, 10, 8, 14, 0, 0, 26, 4, 18, 8, 14, 18, 20, 20, 18, 28, 14, 12, 26, 44, 14, 26, 24, 38, 16, 10, 32, 22, 32, 64, 10, 36, 38, 22, 36, 64, 10, 24, 14, 6, 24, 38, 44, 74, 28, 36, 50, 92, 14, 52, 50, 46, 56, 72, 38, 24, 106, 6, 68, 30, 0, 80, 58, 42, 20, 4