A178753 a(n) = n XOR floor(Log_2(n))+1, where XOR is bitwise XOR.

0, 1, 7, 6, 5, 4, 12, 13, 14, 15, 8, 9, 10, 11, 21, 20, 23, 22, 17, 16, 19, 18, 29, 28, 31, 30, 25, 24, 27, 26, 38, 39, 36, 37, 34, 35, 32, 33, 46, 47, 44, 45, 42, 43, 40, 41, 54, 55, 52, 53, 50, 51, 48, 49, 62, 63, 60, 61, 58, 59, 56, 57, 71, 70, 69, 68, 67, 66, 65, 64, 79, 78

Offset

2,3

Comments

Except for 2 & 3 which are missing, is every integer present just once?

Links

Table of n, a(n) for n=2..73.

Mathematica

f[n_] := BitXor[n, Floor[Log[2, n] + 1]]; t = Array[f, 75, 2];

Crossrefs

Sequence in context: A074921 A182209 A120634 * A377643 A104178 A092874

Adjacent sequences: A178750 A178751 A178752 * A178754 A178755 A178756

Keyword

easy,nonn

Author

Robert G. Wilson v, Jun 09 2010

Status

approved