1,2

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

Index entries for sequences related to trees

a(n) = n*A000055(n).

Cf. A000055, A000169, A055542, A055544.

Sequence in context: A166920 A080206 A132862 this_sequence A049957 A151255 A147999

Adjacent sequences: A055540 A055541 A055542 this_sequence A055544 A055545 A055546

nonn,easy

Eric Weisstein (eric(AT)weisstein.com)

More terms, formula from Christian G. Bower (bowerc(AT)usa.net), Jun 12 2000