A237054 a(1)=1, a(n) = (a(n-1) + n) XOR n.

1, 1, 7, 15, 17, 17, 31, 47, 49, 49, 55, 79, 81, 81, 111, 111, 145, 177, 215, 255, 257, 257, 271, 319, 321, 321, 327, 383, 385, 385, 447, 511, 513, 513, 519, 527, 529, 529, 543, 623, 689, 753, 823, 847, 849, 849, 943, 1007, 1041, 1137, 1175, 1279, 1281, 1281

Offset

1,3

Links

Table of n, a(n) for n=1..54.

Formula

a(1)=1, then a(n) = (a(n-1) + n) XOR n, where XOR is the bitwise exclusive-OR operator.

Prog

(Python)
a=1
for n in range(2, 77):
  print str(a)+', ',
  a = (a+n) ^ n

Crossrefs

Cf. A182389, A182242.

Sequence in context: A180114 A204740 A244536 * A216848 A065566 A329485

Adjacent sequences: A237051 A237052 A237053 * A237055 A237056 A237057

Keyword

nonn,easy

Author

Alex Ratushnyak, Feb 03 2014

Status

approved