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 A366108 #15 Oct 03 2023 10:01:45 %S A366108 1,1,3,5,10,17,35,63,126,231,462,858,1716,3217,6435,12155,24310,46189, %T A366108 92378,176358,352716,676039,1352078,2600150,5200300,10029150,20058300, %U A366108 38779380,77558760,150270097,300540195,583401555,1166803110,2268783825,4537567650,8836315950 %N A366108 a(n) = floor(binomial(n-1, floor((n-1)/2))/2). %H A366108 Gábor Czédli, <a href="https://arxiv.org/abs/2309.13783">Minimum-sized generating sets of the direct powers of the free distributive lattice on three generators and a Sperner theorem</a>, arXiv:2309.13783 [math.CO], 2023. See formulas (3.6) at p. 4 and (4.15) at p. 8. %F A366108 a(n)/A366107(n) ~ 7/4 (see Remark 3.4 at p. 5 in Czédli). %F A366108 a(n) ~ c*2^n/sqrt(n), with c = 1/(2*sqrt(2*Pi)) = A218708. %t A366108 a[n_]:=Floor[Binomial[n-1,Floor[(n-1)/2]]/2]; Array[a,36,3] %o A366108 (PARI) a(n) = binomial(n-1, (n-1)\2)\2; \\ _Michel Marcus_, Sep 30 2023 %Y A366108 Cf. A001405, A004526, A218708, A335322, A366107, A366109. %K A366108 nonn %O A366108 3,3 %A A366108 _Stefano Spezia_, Sep 29 2023