%I #17 Apr 29 2018 19:07:25
%S 0,1,18,198,1300,5895,20646,60028,151848,344925,719290,1399266,
%T 2569788,4496323,7548750,12229560,19206736,29351673,43782498,63913150,
%U 91508580,128746431,178285558,243341748,327771000,436160725,573929226
%N Number of ways to color vertices of a heptagon using <= n colors, allowing rotations and reflections.
%H Harry J. Smith, <a href="/A060532/b060532.txt">Table of n, a(n) for n = 0..200</a>
%H <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (8, -28, 56, -70, 56, -28, 8, -1).
%F a(n) = (n^7+7*n^4+6*n)/14.
%F G.f.: x*(1+10*x+82*x^2+164*x^3+101*x^4+2*x^5)/(1-x)^8. [_Colin Barker_, Jan 29 2012]
%t Table[(n^7+7n^4+6n)/14,{n,0,40}] (* or *) LinearRecurrence[{8,-28,56,-70,56,-28,8,-1},{0,1,18,198,1300,5895,20646,60028},40] (* _Harvey P. Dale_, Aug 15 2016 *)
%o (PARI) { for (n=0, 200, write("b060532.txt", n, " ", (n^7 + 7*n^4 + 6*n)/14); ) } \\ _Harry J. Smith_, Jul 06 2009
%K nonn
%O 0,3
%A _N. J. A. Sloane_, Apr 12 2001