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%I #15 Nov 30 2020 22:37:45
%S 0,1,2,1,4,5,2,1,8,13,10,13,4,9,2,5,16,9,26,17,20,13,26,17,8,5,18,13,
%T 4,1,10,5,32,41,18,25,52,61,34,41,40,53,26,37,52,65,34,45,16,17,10,9,
%U 36,37,26,25,8,13,2,5,20,25,10,13,64,65,82,81,36,37,50
%N For any n >= 0 with binary expansion Sum_{k=0..w} b_k * 2^k, let h(n) = Sum_{k=0..w} b_k * (i-1)^k (where i denotes the imaginary unit); a(n) is the square of the modulus of h(n).
%C See A318438 for the real part of h and additional comments.
%H Rémy Sigrist, <a href="/A318479/b318479.txt">Table of n, a(n) for n = 0..10000</a>
%H <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>
%F a(n) = A318438(n)^2 + A318439(n)^2.
%F a(2^k) = 2^k for any k >= 0.
%F a(3 * 2^k) = 2^k for any l >= 0.
%o (PARI) a(n) = my (d=Vecrev(digits(n, 2))); norm(sum(i=1, #d, d[i]*(I-1)^(i-1)))
%Y Cf. A318438, A318439.
%K nonn,look,base
%O 0,3
%A _Rémy Sigrist_, Aug 27 2018
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