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%I #7 Jul 20 2021 04:59:37
%S 0,1,7,93,2159,15841,6141,44731051,8421119,86113647,3331843885,
%T 127479517837,103104368637,750599904340651,82824819807611,
%U 80500035008073,36170086393773823,49191317521302203051,2460603943675971,12592977287514948283051,89351501819019263845
%N a(n) = 6 * GaussBinomial(2*n, 2, 2) / denominator(Bernoulli(2*n, 1)).
%F a(n) = (4^n - 2)*(4^n - 1)/Clausen(2*n, 1), where Clausen(n, k) = A160014(n, k).
%p a := n -> (4^n - 2)*(4^n - 1) / mul(i, i=select(isprime, map(i->i+1, numtheory[divisors] (2*n)))): seq(a(n), n = 0..20);
%t Table[6 QBinomial[2 n, 2, 2] / Denominator[BernoulliB[2 n, 1]], {n, 0, 20}]
%Y Cf. A006095, A002445, A160014, A346464.
%K nonn
%O 0,3
%A _Peter Luschny_, Jul 19 2021
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