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%I #6 Jul 25 2021 02:41:33
%S 1,7,84,1120,16450,255612,4141382,69158272,1182125043,20581143150,
%T 363704640475,6506965023168,117626432708863,2145180354493274,
%U 39421026305266125,729242353100281344,13568988503585900647,253785064585174078869,4768543107831461199896,89970814565326816488000
%N a(n) = (1/(8*n)) * Sum_{d|n} mu(n/d) * binomial(8*d,d).
%C Inverse Euler transform of A007556.
%C Moebius transform of A261501.
%t Table[(1/(8 n)) Sum[MoebiusMu[n/d] Binomial[8 d, d], {d, Divisors[n]}], {n, 20}]
%o (PARI) a(n) = sumdiv(n, d, moebius(n/d)*binomial(8*d,d))/(8*n); \\ _Michel Marcus_, Jul 24 2021
%Y Cf. A004381, A007556, A008683, A022553, A261501, A346577, A346578, A346579, A346580, A346581.
%K nonn
%O 1,2
%A _Ilya Gutkovskiy_, Jul 24 2021