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 A375346 #30 Jan 31 2025 18:10:33
%S A375346 1,6,38,990,395094,33433683534
%N A375346 Number of orientations of the uniform Lagrangian matroid on n elements.
%C A375346 a(n) is the number of functions F from the powerset of {1, ..., n} to {-1, +1} with F(empty set) = +1 and satisfying the constraint: F({i} union S) != F({j} union S) => F(S) != F({i,j} union S) for any subset S and distinct i,j not in S.
%H A375346 Tobias Boege, Jesse Selover, and Maksym Zubkov, <a href="https://arxiv.org/abs/2407.17826">Sign patterns of principal minors of real symmetric matrices</a>, arXiv:2407.17826 [math.CO], 2024-2025 (see also <a href="https://mathrepo.mis.mpg.de/SymmetricPrincipalMinorSigns/">code and data</a>). See Table 2 on p. 10.
%H A375346 Richard F. Booth, Alexandre V. Borovik, Israel M. Gelfand, and Neil White, <a href="https://doi.org/10.1006/eujc.2000.0485">Oriented Lagrangian Matroids</a>, European Journal of Combinatorics, 22(5) (2001), 639-656.
%F A375346 a(n) = (1/3) * A307334(n) for n >= 2. - _Tobias Boege_, Jan 22 2025
%Y A375346 Cf. A307334.
%K A375346 nonn,more
%O A375346 1,2
%A A375346 _Jesse Selover_, Aug 12 2024
%E A375346 a(6) from _Tobias Boege_, Jan 22 2025