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 A114239 #22 Apr 02 2021 08:38:14 %S A114239 1,18,136,650,2331,6860,17472,39852,83325,162382,298584,522886,878423, %T A114239 1423800,2236928,3419448,5101785,7448874,10666600,15008994,20786227, %U A114239 28373444,38220480,50862500,66931605,87169446,112440888,143748766 %N A114239 a(n) = (n+1)(n+2)^3*(n+3)(n^2 + 4n + 5)/120. %C A114239 Kekulé numbers for certain benzenoids. %C A114239 First differences of A107891. Partial sums of A083200. - _Peter Bala_, Sep 21 2007 %D A114239 S. J. Cyvin and I. Gutman, Kekulé structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (see p. 167, Table 10.5/I/6). %H A114239 Seiichi Manyama, <a href="/A114239/b114239.txt">Table of n, a(n) for n = 0..10000</a> %F A114239 a(n-2) = (n^7-n^3)/(2^7-2^3). - _David Radcliffe_, Dec 27 2008 %F A114239 G.f.: (1+10*x+20*x^2+10*x^3+x^4)/(1-x)^8. - _Colin Barker_, Feb 09 2012 %p A114239 a:=n->(n+1)*(n+2)^3*(n+3)*(n^2+4*n+5)/120: seq(a(n),n=0..33); %o A114239 (PARI) a(n)=n-=2;(n^7-n^3)/120 \\ _Charles R Greathouse IV_, Feb 09 2012 %Y A114239 Cf. A047819, A083200, A107891. %K A114239 nonn,easy %O A114239 0,2 %A A114239 _Emeric Deutsch_, Nov 18 2005