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%I #16 Apr 17 2021 01:26:25
%S 0,6,42,228,1344,7800,46956,279972,1681008,10078164,60474120,
%T 362797116,2176832112,13060694088,78364444284,470185001040,
%U 2821111589856,16926659444832,101559966840108,609359740010604,3656158500550080
%N a(n) = Sum_{d|n} phi(d)*6^(n/d).
%H Seiichi Manyama, <a href="/A054613/b054613.txt">Table of n, a(n) for n = 0..1285</a>
%F a(n) = n * A054625(n).
%F a(n) = Sum_{k=1..n} 6^gcd(n,k). - _Ilya Gutkovskiy_, Apr 16 2021
%o (PARI) a(n) = if(n==0, 0, sumdiv(n, d, eulerphi(d)*6^(n/d))); \\ _Altug Alkan_, Mar 16 2018
%Y Column k=6 of A185651.
%Y Cf. A054625.
%K nonn
%O 0,2
%A _N. J. A. Sloane_, Apr 16 2000
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