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%I #15 Aug 10 2021 11:05:25
%S 1,2,3,11,33,309,665,1461,2323,6789
%N Numbers m such that m^2 divides A159068(m), where A159068(m) = Sum_{k=1..m} binomial(m,k) * gcd(m,k).
%C m divides A159068(m) for all positive integers m.
%o (PARI) is(m) = sum(k=1, m, binomial(m, k)*gcd(k, m))%m^2 == 0; \\ _Jinyuan Wang_, Aug 10 2021
%Y Cf. A159068, A159069.
%K nonn,more
%O 1,2
%A _Leroy Quet_, Apr 12 2009
%E 4 more terms from _R. J. Mathar_, Apr 16 2009
%E a(10)=6789 from _Ray Chandler_, Jun 19 2009
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