cp's OEIS Frontend

A199396 Binary XOR of (3^k - 1)/2 as k varies from 1 to n.

%I A199396 #18 Nov 03 2015 09:38:32
%S A199396 1,5,8,32,89,309,1392,2464,12241,23685,66936,329856,598377,2972885,
%T A199396 4204000,17321536,47254689,156943365,737779176,1276350496,6369950073,
%U A199396 12290868597,35051319632,175157734688,319624706161,1569854375813,2311734655064,9333158201280,25600877525257
%N A199396 Binary XOR of (3^k - 1)/2 as k varies from 1 to n.
%H A199396 Paul D. Hanna, <a href="/A199396/b199396.txt">Table of n, a(n) for n = 1..365</a>
%e A199396 a(2) = (3^1-1)/2 XOR (3^2-1)/2 = 1 XOR 4 = 5;
%e A199396 a(3) = (3^1-1)/2 XOR (3^2-1)/2 XOR (3^3-1)/2 = 1 XOR 4 XOR 13 = 8;
%e A199396 a(4) = (3^1-1)/2 XOR (3^2-1)/2 XOR (3^3-1)/2 XOR (3^4-1)/2 = 1 XOR 4 XOR 13 XOR 40 = 32.
%t A199396 FoldList[BitXor, Table[(3^n - 1)/2, {n, 1, 29}]] (* _Vladimir Reshetnikov_, Nov 02 2015 *)
%o A199396 (PARI) {a(n)=if(n<=0,0,bitxor(a(n-1),(3^n-1)/2))}
%Y A199396 Cf. A199397, A199403, A199402, A000975.
%K A199396 nonn
%O A199396 1,2
%A A199396 _Paul D. Hanna_, Nov 05 2011