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%I #8 Jun 10 2016 04:46:11
%S 1,6,3150,12612600,192972780000,8046096548490000,
%T 747480957758835300000,135330984231708815550000000,
%U 43401712634861734607093640000000,22953694145310867501311470722000000000,18935469872719334117190133449041218500000000
%N Number of unrooted labeled trees on 4n+2 nodes with node degree either one or five.
%C There are no unrooted labeled trees on 4n or 4n+1 or 4n+3 nodes with node degree either one or five.
%H Math.Stackexchange.com, Marko Riedel et al., <a href="http://math.stackexchange.com/questions/1816933/">Number of labeled trees</a>
%p seq(binomial(4*n+2, n)*(4*n)!/4!^n, n=0..20);
%t Table[Binomial[4*n+2, n]*(4*n)!/(4!)^n, {n,0,10}] (* _G. C. Greubel_, Jun 09 2016 *)
%Y Cf. A274056, A000272, A274081.
%K nonn
%O 0,2
%A _Marko Riedel_, Jun 09 2016
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