%I #18 Oct 12 2024 21:33:27
%S 0,-512,-80,0,8649641728,1133799040000,45191047171248,909911473891840,
%T 11606509936046080,106382489775763968,758004524485390000,
%U 4426707303695531008,21997505178850901760,95618498598830172160,371276621337370572208,1308990920184354240000,4245218136262184992768,12798230144932688135680
%N Characteristic polynomial of the Pappus graph: a(n) = (n-3)*n^4*(n+3)*(n^2-3)^6.
%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PappusGraph.html">Pappus Graph</a>.
%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Pappus_graph">Pappus graph</a>.
%H Wolframalpha, <a href="https://www.wolframalpha.com/input?i=Pappus+graph">Pappus graph</a>.
%H <a href="/index/Rec#order_19">Index entries for linear recurrences with constant coefficients</a>, signature (19,-171,969,-3876,11628,-27132,50388,-75582,92378,-92378,75582,-50388,27132,-11628,3876,-969,171,-19,1).
%F a(n) = (n-3)*n^4*(n+3)*(n^2-3)^6.
%o (Python)
%o a = lambda n: (n-3)*(n**4)*(n+3)*(n**2-3)**6
%o print([a(n) for n in range(0, 18)])
%o (PARI) a(n)=(n-3)*(n+3)*n^4*(n^2-3)^6 \\ _Charles R Greathouse IV_, Oct 12 2024
%o (Python)
%o def A376951(n): return (m:=n**2)**2*(m-9)*(m-3)**6 # _Chai Wah Wu_, Oct 12 2024
%Y Cf. A110507.
%K sign,easy
%O 0,2
%A _DarĂo Clavijo_, Oct 10 2024