A126022 a(1)=1; for n>1, a(n) = a(n-1) + (the number of terms of {a(k)} which are <= n).

1, 2, 4, 7, 10, 13, 17, 21, 25, 30, 35, 40, 46, 52, 58, 64, 71, 78, 85, 92, 100, 108, 116, 124, 133, 142, 151, 160, 169, 179, 189, 199, 209, 219, 230, 241, 252, 263, 274, 286, 298, 310, 322, 334, 346, 359, 372, 385, 398, 411, 424, 438, 452, 466, 480, 494, 508

Offset: 1

Author

Leroy Quet, Feb 27 2007

Keywords

• easy
• nonn

Examples

			There are four terms (1,2,4,7) of the sequence which are <= 9. So a(9) = a(8) + 4 = 25.
		

Programs

Mathematica

f[l_] := Block[{s = Length@l + 2}, Append[l, Last@l + Length@Select[l, # < s &]]]; Nest[f, {1}, 56] (* Robert G. Wilson v, Mar 01 2007 *)

Extensions

More terms from Robert G. Wilson v, Mar 01 2007