A self-generating sequence: every positive integer occurs as a(i)-a(j) for a unique pair i,j.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =16a(5) =21a(6) =42a(7) =51a(8) =102a(9) =112a(10) =224a(11) =235a(12) =470a(13) =486a(14) =972a(15) =990a(16) =1980a(17) =2002a(18) =4004a(19) =4027a(20) =8054a(21) =8078a(22) =16156a(23) =16181a(24) =32362a(25) =32389a(26) =64778a(27) =64806a(28) =129612a(29) =129641