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A080263
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A014486-encoding of the branch-reduced binomial-mod-2 binary trees.
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13
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2, 50, 906, 247986, 4072138, 1059204274, 272900475786, 17953590946285746, 287705670922216138, 73724537815637830834, 18880972926031430339466, 1237678872789190922262530226, 316876593058175709191975346890
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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COMMENTS
| These trees are obtained from the successive generations of Rule 90 cellular automaton (A070886) or the Pascal's triangle computed modulo 2 (A047999), with alive cells of the automaton (respectively: the odd binomials) forming the vertices of the zigzag tree.
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REFERENCES
| J.C.P. Miller, Periodic Forests of Stunted Trees, Phil. Tran. Roy. Soc. London A266 (1970) 63; A293 (1980) 48.
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LINKS
| A. Karttunen, Initial terms illustrated
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CROSSREFS
| Same sequence in binary: A080264. Cf. A080265. Breadth-first-wise encodings of the same trees: A080268. Corresponding branch-reduced zigzag trees: A080293.
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.
Sequence in context: A080299 A083939 A083941 * A088920 A079198 A203766
Adjacent sequences: A080260 A080261 A080262 * A080264 A080265 A080266
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KEYWORD
| nonn
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AUTHOR
| Antti Karttunen (my_firstname.my_surname(AT)iki.fi), Mar 02 2003
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