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%I #16 Oct 31 2017 20:54:10
%S 70,8296,1398500,268447936,54975633976,11728126132976,
%T 2573485510942780,576460752706101376,131176846748288854980,
%U 30223145490448192851232,7033750223212787748164020,1650586719047191292234702976,390046338531762979375904093800
%N Number of distinct n X 4 toroidal 0..3 arrays.
%H Andrew Howroyd, <a href="/A184275/b184275.txt">Table of n, a(n) for n = 1..100</a>
%t T[n_, k_] := (1/(n*k))*Sum[Sum[EulerPhi[c]*EulerPhi[d]*4^(n*k/LCM[c, d]), {d, Divisors[k]}], {c, Divisors[n]}]; a[n_] := T[n, 4]; Array[a, 13] (* _Jean-François Alcover_, Oct 31 2017, after _Andrew Howroyd_ *)
%Y Column 4 of A184277.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 10 2011
%E Terms a(7) and beyond from _Andrew Howroyd_, Sep 27 2017
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