# how to find the number of trees on 18 vertices that have diameter=5 and product of 2nd smallest laplacian eigenvalue(algebraic connectivity)and largest laplacian eigenvalue is equal to 1.
If we increase the number of vertices say above 18 why it gives no result?

how to find the number of trees on 18 vertices that have diameter=5 and product of 2nd smallest laplacian eigenvalue(algebraic connectivity)and largest laplacian eigenvalue is equal to 1.

Perhaps this question is related to https://ask.sagemath.org/question/385...

Do you know the difference between a title and a question? That would help the readers a lot!

Thanks for your suggestion.