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 A129023 #3 Mar 30 2012 16:50:41 %S A129023 1,1,1,3,6,7,6,12,28,26,28,51 %N A129023 Isomer numbers for the indacenoid constant-isomer series. %C A129023 This allows two single pentagonal rings among otherwise hexagonal rings. %C A129023 The terms occur in groups of 4: X, Y, X, Y, ... %D A129023 J. Brunvoll, B. N. Cyvin, S. J. Cyvin, G. Brinkmann and J. Bornhoft, Z. Naturforsch., 51a, 1073 (1996). %D A129023 S. J. Cyvin, B. N. Cyvin and J. Brunvoll, J. Molec. Struct. (Theochem), 281, 229 (1993). %D A129023 J. R. Dias, Chem. Phys. Lett., 185, 10 (1991). %D A129023 J. R. Dias, J. Chem. Inf. Comput. Sci., 32, 203-209 (1992). (*) %D A129023 J. R. Dias, J. Chem. Inf. Comput. Sci. 33, 117 (1993). %D A129023 J. R. Dias, Discr. App. Math., 67, 79 (1996). %D A129023 J. R. Dias, The Periodic Table Set as a Unifying Concept in Going from Benzenoid Hydrocarbons to Fullerene Carbons, in "The Periodic Table: Into the 21st Century", Edited by D.H. Rouvray and R. B. King, Research Studies Press Ltd, Baldock, Hertfordshire, England, 2004, 371-396. [See Section 5.2.] %Y A129023 Cf. A129012-A129022. %K A129023 nonn %O A129023 0,4 %A A129023 _N. J. A. Sloane_, May 10 2007