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 A108675 #12 Jul 22 2022 09:37:15 %S A108675 1,21,157,707,2353,6405,15106,31998,62349,113641,196119,323401,513149, %T A108675 787801,1175364,1710268,2434281,3397485,4659313,6289647,8369977, %U A108675 10994621,14272006,18326010,23297365,29345121,36648171,45406837 %N A108675 a(n) = (n+1)*(n+2)*(61*n^4 + 366*n^3 + 845*n^2 + 888*n + 360)/720. %C A108675 Kekulé numbers for certain benzenoids. %D A108675 S. J. Cyvin and I. Gutman, Kekulé structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (p. 231, # 35). %H A108675 R. P. Stanley, <a href="/A002721/a002721.pdf">Examples of Magic Labelings</a>, Unpublished Notes, 1973 [Cached copy, with permission] See p. 31. %H A108675 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (7,-21,35,-35,21,-7,1). %F A108675 G.f.: (1 + 14*x + 31*x^2 + 14*x^3 + x^4)/(1-x)^7. %p A108675 a:=n->(n+1)*(n+2)*(61*n^4+366*n^3+845*n^2+888*n+360)/720: seq(a(n),n=0..32); %K A108675 nonn,easy %O A108675 0,2 %A A108675 _Emeric Deutsch_, Jun 17 2005