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 A121187 #14 Jul 29 2023 14:34:36 %S A121187 1,4,22,126,686,3640,19470,103889,558389,3019000,16443467 %N A121187 Alkane systems (see Cyvin reference for precise definition). %H A121187 S. J. Cyvin, B. N. Cyvin, J. Brunvoll, and J. Wang, <a href="https://doi.org/10.1016/S0022-2860(97)00419-5">Enumeration of staggered conformers of alkanes and monocyclic cycloalkanes</a>, J. Molec. Struct., 445 (1998), 127-137. See Table 3, branched, column "Stereo-isomers". %H A121187 S. J. Cyvin, Jianji Wang, J. Brunvoll, Shiming Cao, Ying Li, B. N. Cyvin, and Yugang Wang, <a href="https://doi.org/10.1016/S0022-2860(97)00025-2">Staggered conformers of alkanes: complete solution of the enumeration problem</a>, J. Molec. Struct. 413-414 (1997), 227-239. See Table 6, branched, column "Stereo-isomers". %K A121187 nonn,more %O A121187 4,2 %A A121187 _N. J. A. Sloane_, Aug 17 2006