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

%I

%S 1,2,11,16,65,178,619,2784,4929,24482,47371,133872,659713,1196754,

%T 5945771,8408000,34643073,94509378,313886731,1475558352,2552700993,

%U 12739900146,24581737195,70102639264,350315469377,639249412322,3139708751627,4623469310128,18666316402561

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

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

%H Paul D. Hanna, <a href="/A199397/b199397.txt">Table of n, a(n) for n = 0..300</a>

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

%p A[0]:= 1:

%p for n from 1 to 40 do

%p A[n]:= Bits:-Xor(A[n-1],3^n)

%p od:

%p seq(A[i],i=0..40); # _Robert Israel_, Nov 02 2015

%t FoldList[BitXor, 3^Range[0, 28]] (* _Vladimir Reshetnikov_, Nov 02 2015 *)

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

%Y Cf. A199396.

%K nonn,base

%O 0,2

%A _Paul D. Hanna_, Nov 05 2011

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Last modified October 21 21:25 EDT 2021. Contains 348155 sequences. (Running on oeis4.)