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%I #27 May 03 2023 09:13:25
%S 1,15,85,771,4369,65535,327685,3342387,16843009,252645135,1431655765,
%T 12884901891,73014444049,1095216660735,5519032976645,56294136361779,
%U 281479271743489,4222189076152335,23925738098196565
%N Trisection of A001317.
%C For n>=1, all terms are in A001969.
%C Or rows of triangle A008287 mod 2 converted to decimal.
%H Gheorghe Coserea, <a href="/A177882/b177882.txt">Table of n, a(n) for n = 0..200</a>
%F a(n) = A001317(3*n).
%t f[n_] := BitXor[n, BitShiftLeft[n, 1]]; Table[Nest[f, 1, x], {x, 0, 54, 3}]
%o (PARI)
%o a(n) = subst(lift(Pol(Mod([1, 1, 1, 1], 2), 'x)^n), 'x, 2);
%o vector(19, n, a(n-1)) \\ _Gheorghe Coserea_, Jun 12 2016
%o (Python)
%o def A177882(n): return sum((bool(~(3*n)&3*n-k)^1)<<k for k in range(3*n+1)) # _Chai Wah Wu_, May 02 2023
%Y Cf. A001317, A001969, A005190, A007318, A008287.
%K nonn
%O 0,2
%A _Vladimir Shevelev_, Dec 14 2010
%E Definition rewritten by _N. J. A. Sloane_, Jan 01 2011
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