A125568 a(0)=1. For n>=1, n-th run consists of the integers (in ascending order) of n through a(n-1)+n-1.

1, 1, 2, 3, 4, 4, 5, 6, 5, 6, 7, 8, 6, 7, 8, 9, 7, 8, 9, 10, 11, 8, 9, 10, 11, 12, 13, 9, 10, 11, 12, 13, 10, 11, 12, 13, 14, 15, 11, 12, 13, 14, 15, 16, 17, 12, 13, 14, 15, 16, 17, 18, 19, 13, 14, 15, 16, 17, 18, 14, 15, 16, 17, 18, 19, 20, 15, 16, 17, 18, 19, 20, 21, 22, 16, 17, 18

Offset

0,3

Links

Table of n, a(n) for n=0..76.

Example

The sequence grouped by (ascending) runs, where the n-th run, for n>=1, consists of a(n-1) integers: 1, (1), (2), (3, 4), (4, 5, 6), (5, 6, 7, 8), (6, 7, 8, 9), (7, 8, 9, 10, 11), (8, 9, 10, 11, 12, 13), (9, 10, 11, 12, 13), ...

Mathematica

f[l_List] := Block[{n = Length[l]}, Append[l, Range[n, Flatten[l][[n]] + n - 1]]]; Flatten@Nest[f, {{1}}, 16] (* Ray Chandler, Jan 05 2007 *)

Crossrefs

Sequence in context: A058222 A064064 A101504 * A248110 A108872 A147847

Adjacent sequences: A125565 A125566 A125567 * A125569 A125570 A125571

Keyword

easy,nonn

Author

Leroy Quet, Jan 01 2007

Extensions

Extended by Ray Chandler, Jan 05 2007

Status

approved