A199397 Binary XOR of 3^k as k varies from 0 to n.

1, 2, 11, 16, 65, 178, 619, 2784, 4929, 24482, 47371, 133872, 659713, 1196754, 5945771, 8408000, 34643073, 94509378, 313886731, 1475558352, 2552700993, 12739900146, 24581737195, 70102639264, 350315469377, 639249412322, 3139708751627, 4623469310128, 18666316402561

Offset: 0

Author

Paul D. Hanna, Nov 05 2011

Keywords

• nonn
• base

Comments

Appears to be a self-convolution of an integer sequence (true for at least the initial 761 terms).

Examples

			a(2) = 1 XOR 3 = 2; a(3) = 1 XOR 3 XOR 9 = 11; a(4) = 1 XOR 3 XOR 9 XOR 27 = 16.
		

Links

• Paul D. Hanna, Table of n, a(n) for n = 0..300

Crossrefs

Cf. A199396.

Programs

Maple

A[0]:= 1:
for n from 1 to 40 do
  A[n]:= Bits:-Xor(A[n-1],3^n)
od:
seq(A[i],i=0..40); # Robert Israel, Nov 02 2015

Mathematica

FoldList[BitXor, 3^Range[0, 28]] (* Vladimir Reshetnikov, Nov 02 2015 *)

PARI

{a(n)=if(n<0,0,bitxor(a(n-1),3^n))}