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%I #6 Jan 02 2023 12:30:54
%S 6,2,20,3,1008,4,72,5,4400,144,835660800,7,10800,8,272,9,9849600,400,
%T 208039104,11,145520912351232000000,64281600,
%U 3608344625286776094720000,13,1296,84672,90944,129600
%N a(n) is the least integer m such that A047994(m) = ((n-2)/n)*m where A047994 is the unitary totient function, or 0 if there is no such m.
%H Yasutoshi Kohmoto, <a href="http://list.seqfan.eu/oldermail/seqfan/2018-August/018717.html">UnitaryPhi</a>, SeqFan list, Aug-Sep 2018.
%F a(2n) = A318842(n).
%o (PARI) \\ uses the "solve_uphi pari code", see A318842 links
%o a(n) = {my(lim = 1, v); while (1, v = solve_uphi(n-2, n, lim); if (#v, return (v[1])); lim *= 10; ); }
%Y Cf. A047994 (unitary totient).
%Y Cf. A030163, A305678, A318842.
%K nonn,more
%O 3,1
%A _Michel Marcus_, Sep 17 2018
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