A118028 a(0)=1. a(n) = a(n-1) + (smallest integer which is >= n and is missing from the earlier terms of the sequence).

1, 3, 5, 9, 13, 19, 25, 32, 40, 50, 60, 71, 83, 97, 111, 126, 142, 159, 177, 197, 217, 238, 260, 283, 307, 333, 359, 386, 414, 443, 473, 504, 537, 570, 604, 639, 675, 712, 750, 789, 830, 871, 913, 956, 1000, 1045, 1091, 1138, 1186, 1235, 1286, 1337, 1389, 1442

Offset: 0

Author

Leroy Quet, Apr 10 2006

Keywords

• easy
• nonn

Links

• Michael De Vlieger, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A118026, A118027, A118029, A118030, A094589.

Programs

Mathematica

a = {1}; Do[k = 2; While[Nand[FreeQ[a, k], k >= i], k++]; AppendTo[a, a[[i]] + k], {i, 53}]; a (* Michael De Vlieger, Sep 19 2017 *)

Extensions

More terms from Joshua Zucker, Jul 27 2006