1,1

Eric Weisstein's World of Mathematics, Weakly Binary Tree.

Sum of all 1-digit Wedderburn-Etherington numbers is 14.

Sum of all 2-digit Wedderburn-Etherington numbers is 178.

Sum of all 3-digit Wedderburn-Etherington numbers is 1641.

Cf. A001190.

Sequence in context: A061484 A097583 A125471 this_sequence A126866 A133286 A097828

Adjacent sequences: A132007 A132008 A132009 this_sequence A132011 A132012 A132013

nonn,base

Parthasarathy Nambi (PachaNambi(AT)yahoo.com), Oct 29 2007