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%I #28 Sep 08 2022 08:46:13
%S 0,18,93312,4737042,51775488,263351250,807055488,1609827282,
%T 1934917632,774840978,691920000,20514061458,126428055552,496767242322,
%U 1543426109568,4122612551250,9879830396928,21788831695122,44962051370112,87830997546258,163819480320000
%N a(n) = 18*n^4*(2*n^3 - 23*n^2 + 38*n - 18)^2.
%H M. P. Delest, <a href="http://dx.doi.org/10.1016/0097-3165(88)90071-4">Generating functions for column-convex polyominoes</a>, J. Combin. Theory Ser. A 48 (1988), no. 1, pp. 12-31.
%H <a href="/index/Rec#order_11">Index entries for linear recurrences with constant coefficients</a>, signature (11,-55,165,-330,462,-462,330,-165,55,-11,1).
%F G.f.: 18*x*(1 + 5173*x + 206200*x^2 + 266512*x^3 - 3390686*x^4 + 389794*x^5 + 10761232*x^6 + 5689720*x^7 + 580693*x^8 + 6561*x^9)/(1-x)^11.
%F a(n) = 11*a(n-1) - 55*a(n-2) + 165*a(n-3) - 330*a(n-4) + 462*a(n-5) - 462*a(n-6) + 330*a(n-7) - 165*a(n-8) + 55*a(n-9) - 11*a(n-10) + a(n-11).
%p A259364:=n->18*n^4*(2*n^3 - 23*n^2 + 38*n - 18)^2: seq(A259364(n), n=0..30); # _Wesley Ivan Hurt_, Apr 12 2017
%t Table[18 n^4 (2 n^3 - 23 n^2 + 38 n - 18)^2, {n, 0, 23}]
%o (Magma) [18*n^4*(2*n^3-23*n^2+38*n-18)^2: n in [0..20]];
%o (Sage) [2*(6*n^5-69*n^4+114*n^3-54*n^2)^2 for n in (0..20)] # _Bruno Berselli_, Jun 25 2015
%Y Cf. A001105, A005435.
%K nonn,easy
%O 0,2
%A _Vincenzo Librandi_, Jun 25 2015
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