A120241 a(n) = (n - 2^floor(log(n)/log(2)) + 1)-th integer among those positive integers not among the earlier terms of the sequence.
1, 2, 4, 3, 6, 8, 10, 5, 9, 12, 14, 16, 18, 20, 22, 7, 13, 17, 21, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 11, 19, 25, 29, 33, 37, 41, 45, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 15, 27, 35, 43, 49, 53, 57, 61, 65
Offset: 1
Examples
The first 6 terms of the sequence are 1,2,4,3,6,8. Now 7 - 2^floor(log(7)/log(2)) + 1 = 4. So we want the 4th term of those positive integers not occurring among the first 6 terms of the sequence (i.e., the 4th term among 5,7,9,10,11,...). So a(7) = 10.
Links
- Ivan Neretin, Table of n, a(n) for n = 1..8191
Programs
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Mathematica
Fold[Append[#1, Complement[Range[Max[#1] + #2], #1][[#2]]] &, {1}, Flatten@Table[Range[2^k], {k, 6}]] (* Ivan Neretin, Sep 24 2021 *)
Extensions
Extended by Ray Chandler, Jun 19 2006
Comments