%I A005419 M3023
%S A005419 1,1,3,16,112,1020,10222,109947,1230840,14218671,168256840,2031152928,
%T A005419 24931793768,310420597116,3912823963482,49853370677834,
%U A005419 641218583442360,8316918403772790,108686334145327785
%N A005419 Number of ways of dissecting a polygon into n 7-gons.
%D A005419 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A005419 F. Harary, E. M. Palmer and R. C. Read, On the cell-growth problem for 
               arbitrary polygons, Discr. Math. 11 (1975), 371-389.
%F A005419 See Mathematica code.
%t A005419 p=7; Table[(Binomial[(p-1)n, n]/(((p-2)n+1)((p-2)n+2)) + If[OddQ[n], 
               If[OddQ[p], Binomial[(p-1)n/2, (n-1)/2]/n, (p+1)Binomial[((p-1)n-1)/
               2, (n-1)/2]/((p-2)n+2)], 3Binomial[(p-1)n/2, n/2]/((p-2)n+2)]+Plus 
               @@ Map[EulerPhi[ # ]Binomial[((p-1)n+1)/#, (n-1)/# ]/((p-1)n+1)&, 
               Complement[Divisors[GCD[p, n-1]], {1, 2}]])/2, {n, 1, 20}] - Robert 
               A. Russell (russell(AT)post.harvard.edu), Dec 11 2004
%Y A005419 Sequence in context: A141003 A002404 A097142 this_sequence A124537 A074523 
               A042437
%Y A005419 Adjacent sequences: A005416 A005417 A005418 this_sequence A005420 A005421 
               A005422
%K A005419 nonn
%O A005419 1,3
%A A005419 N. J. A. Sloane (njas(AT)research.att.com).
%E A005419 More terms from Robert A. Russell (russell(AT)post.harvard.edu), Dec 
               11 2004