A274083 Number of unrooted labeled trees on 4n+2 nodes with node degree either one or five.

1, 6, 3150, 12612600, 192972780000, 8046096548490000, 747480957758835300000, 135330984231708815550000000, 43401712634861734607093640000000, 22953694145310867501311470722000000000, 18935469872719334117190133449041218500000000

Offset: 0

Author

Marko Riedel, Jun 09 2016

Keywords

• nonn

Comments

There are no unrooted labeled trees on 4n or 4n+1 or 4n+3 nodes with node degree either one or five.

Links

• Math.Stackexchange.com, Marko Riedel et al., Number of labeled trees

Crossrefs

Cf. A274056, A000272, A274081.

Programs

Maple

seq(binomial(4*n+2, n)*(4*n)!/4!^n, n=0..20);

Mathematica

Table[Binomial[4*n+2, n]*(4*n)!/(4!)^n, {n,0,10}] (* G. C. Greubel, Jun 09 2016 *)