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 A005961 M1447 #26 Dec 29 2024 00:52:56 %S A005961 1,2,5,13,37,108,325,993,3070,9564,29979,94392,298311,945592,3005021, %T A005961 9570559,30539044,97611676,312462096,1001554565,3214232129, %U A005961 10326580526,33210135104,106901289420,344398593149,1110395171502,3582666470285,11567123373968 %N A005961 Number of acyclic disubstituted alkanes with n carbon atoms and identical substituents. %C A005961 Acyclic alkanes of the form C_nH_mX2. - _Sean A. Irvine_, Nov 12 2016 %D A005961 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A005961 R. C. Read, <a href="/A000598/a000598.pdf">The Enumeration of Acyclic Chemical Compounds</a>, pp. 25-61 of A. T. Balaban, ed., Chemical Applications of Graph Theory, Ac. Press, 1976. [Annotated scanned copy] See p. 44. %F A005961 G.f.: -1 + (1/(1-x*B(x)^2) + 1/(1-x*B(x^2)))/2 where B(x) is the g.f. for A000625. - _Sean A. Irvine_, Nov 12 2016 %Y A005961 Cf. A005960. %K A005961 nonn %O A005961 1,2 %A A005961 _N. J. A. Sloane_ %E A005961 More terms and title improved by _Sean A. Irvine_, Nov 12 2016