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Number of palindromic structures using exactly five different symbols.
1

%I #13 Aug 22 2017 20:53:12

%S 0,0,0,0,0,0,0,0,1,1,15,15,140,140,1050,1050,6951,6951,42525,42525,

%T 246730,246730,1379400,1379400,7508501,7508501,40075035,40075035,

%U 210766920,210766920,1096190550

%N Number of palindromic structures using exactly five different symbols.

%C Permuting the symbols will not change the structure.

%D M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia. [See A056391 for pdf file of Chap. 2]

%H <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (1,14,-14,-71,71,154,-154,-120,120).

%F stirling2( [(n+1)/2], 5).

%F G.f.: -x^9/((x-1)*(2*x-1)*(2*x+1)*(2*x^2-1)*(3*x^2-1)*(5*x^2-1)). [_Colin Barker_, Jul 24 2012]

%t Table[StirlingS2[Floor[(n+1)/2],5],{n,40}] (* _Harvey P. Dale_, Dec 18 2012 *)

%Y Cf. A000481, A056470.

%K nonn,easy

%O 1,11

%A _Marks R. Nester_