A080263 - OEIS

%I #7 Dec 02 2018 23:13:40

%S 2,50,906,247986,4072138,1059204274,272900475786,17953590946285746,

%T 287705670922216138,73724537815637830834,18880972926031430339466,

%U 1237678872789190922262530226,316876593058175709191975346890

%N A014486-encoding of the branch-reduced binomial-mod-2 binary trees.

%C These trees are obtained from the successive generations of Rule 90 cellular automaton (A070886) or Pascal's triangle computed modulo 2 (A047999), with alive cells of the automaton (respectively: the odd binomials) forming the vertices of the zigzag tree.

%D J. C. P. Miller, Periodic Forests of Stunted Trees, Phil. Tran. Roy. Soc. London A266 (1970) 63; A293 (1980) 48.

%H A. Karttunen, <a href="/A080263/a080263.pdf">Initial terms illustrated</a>

%Y Same sequence in binary: A080264. Cf. A080265. Breadth-first-wise encodings of the same trees: A080268. Corresponding branch-reduced zigzag trees: A080293.

%Y Number of edges in general trees/internal nodes in binary trees: A006046, number of zigzag-edges (those colored black in illustrations) is one less: A074330. Cf. A080978.

%K nonn

%O 0,1

%A _Antti Karttunen_, Mar 02 2003