A068012 Number of subsets of {1,2,3,...,n} that sum to 0 mod 6.

1, 1, 1, 2, 3, 6, 12, 22, 44, 88, 172, 344, 688, 1368, 2736, 5472, 10928, 21856, 43712, 87392, 174784, 349568, 699072, 1398144, 2796288, 5592448, 11184896, 22369792, 44739328, 89478656, 178957312, 357914112, 715828224, 1431656448, 2863311872