A078474 a(1)=a(2)=a(3)=1, a(n)=n-a(a(n-1))-a(a(n-2))-a(a(n-3)).

1, 1, 1, 1, 2, 3, 4, 5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 9, 10, 11, 12, 12, 12, 12, 13, 14, 15, 16, 16, 16, 16, 17, 18, 19, 20, 20, 20, 20, 21, 22, 23, 24, 24, 24, 24, 25, 25, 25, 25, 26, 26, 26, 26, 27, 27, 27, 27, 28, 29, 30, 31, 31, 31, 31, 32, 32, 32, 32, 33, 33, 33