This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A346925 #6 Aug 07 2021 21:34:24
%S A346925 1,2,11,52,272,1414,7751,43208,246663,1430440,8414639,50065628,
%T A346925 300830571,1822758766,11124755380,68328711696,422030545334,
%U A346925 2619630794574,16332922290299,102240108466928,642312451209982,4048514835624478,25594403741131679,162250237951706584
%N A346925 a(n) = Sum_{d|n} mu(n/d) * binomial(3*d,d) / (2*d+1).
%C A346925 Moebius transform of A001764.
%t A346925 Table[Sum[MoebiusMu[n/d] Binomial[3 d, d]/(2 d + 1), {d, Divisors[n]}], {n, 24}]
%o A346925 (PARI) a(n) = sumdiv(n, d, moebius(n/d)*binomial(3*d, d)/(2*d+1)); \\ _Michel Marcus_, Aug 07 2021
%Y A346925 Cf. A001764, A002996, A008683.
%K A346925 nonn
%O A346925 1,2
%A A346925 _Ilya Gutkovskiy_, Aug 07 2021