A182389 a(0)=1, a(n) = (a(n-1) + n) XOR n.

1, 3, 7, 9, 9, 11, 23, 25, 41, 59, 79, 81, 81, 83, 111, 113, 145, 179, 215, 249, 281, 315, 327, 329, 377, 395, 447, 449, 449, 451, 511, 513, 513, 515, 519, 521, 521, 523, 535, 537, 617, 699, 719, 721, 721, 723, 815, 881, 913, 1011, 1047, 1145, 1177, 1275, 1287

Offset

0,2

Comments

a(n) >= n.

a(n) >= a(n-1). - Daniel Leary, Aug 21 2016

Links

Paolo Xausa, Table of n, a(n) for n = 0..10000 (terms 0..1000 from Ivan Panchenko)

Formula

a(0)=1, a(n)=(a(n-1) + n) XOR n, where XOR is the bitwise exclusive-OR operator.

Example

a(5) = (a(4)+5) XOR 5 = (9+5) XOR 5 = 14 XOR 5 = 11.

Mathematica

Module[{n = 0}, NestList[BitXor[++n, # + n] &, 1, 100]] (* Paolo Xausa, Nov 26 2024 *)

Prog

(Python)
a=1
for i in range(1, 55):
    print(a, end=', ')
    a += i
    a ^= i

Crossrefs

Cf. A182242, A182247, A237054.

Sequence in context: A331066 A179021 A096910 * A279615 A169968 A082768

Adjacent sequences: A182386 A182387 A182388 * A182390 A182391 A182392

Keyword

nonn,base,easy

Author

Alex Ratushnyak, Apr 27 2012

Status

approved