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 A007143 E-trees with exactly 2 colors. (Formerly M3013) 0
 0, 0, 3, 16, 65, 238, 866, 3128, 11493, 42660, 160584, 610640, 2345504, 9081768, 35422175, 139022622, 548671517, 2176051050, 8668363573, 34667284390, 139140830956, 560271494630, 2262709876003, 9163000968554, 37198940600264, 151364381618576 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 REFERENCES G. Gati, F. Harary and R. W. Robinson, Line colored trees with extendable automorphisms, Acta Math. Scientia, 2 (1982), 105-110. N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS G. Gati, F. Harary, R. W. Robinson, Line colored trees with extendable automorphisms, Acta Mathematica Scientia 2.1 (1982), 105-110. (Annotated scanned copy) FORMULA a(n) = A007141(n) - 2 * A003238(n) for n > 1. - Sean A. Irvine, Oct 30 2017 CROSSREFS Sequence in context: A267036 A037451 A247363 * A062960 A293579 A044046 Adjacent sequences:  A007140 A007141 A007142 * A007144 A007145 A007146 KEYWORD nonn AUTHOR EXTENSIONS a(8) corrected and more terms from Sean A. Irvine, Oct 30 2017 STATUS approved

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Last modified June 2 14:12 EDT 2020. Contains 334782 sequences. (Running on oeis4.)