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 A223095 Number of foldings of n labeled stamps in which both end leaves are inwards. 2
 0, 0, 0, 2, 10, 40, 156, 546, 1986, 6716, 23742, 79472, 277178, 925588, 3205896, 10711486, 36963722, 123712788, 426075994, 1429030624, 4916833424, 16526958144, 56840484232, 191466923584, 658460090994, 2222507917328, 7644360501390, 25850724646008, 88938175307354 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS Subset of foldings of n labeled stamps (A000136). - Stéphane Legendre, Apr 09 2013 LINKS Stéphane Legendre, Table of n, a(n) for n = 1..42 S. Legendre, Foldings and Meanders, arXiv preprint arXiv:1302.2025 [math.CO], 2013. S. Legendre, Foldings and Meanders, Aust. J. Comb. 58(2), 275-291, 2014. FORMULA a(n) = A223094(n) - A223093(n). - Andrew Howroyd, Dec 06 2015 a(n) = A000136(n) + A077014(n) - 2 * A000682(n). - Andrew Howroyd, Dec 06 2015 A217318(n) = a(n) if n is odd and A217318(n) = (1/2)*a(n) if n is even. - Stéphane Legendre, Jan 13 2014 MATHEMATICA A217318 = Import["https://oeis.org/A217318/b217318.txt", "Table"][[All, 2]]; a[n_] := (2 - Mod[n, 2]) A217318[[n]]; Array[a, 42] (* Jean-François Alcover, Sep 02 2019 *) CROSSREFS Cf. A000136, A000682, A077014. Cf. A223093, A223094. Sequence in context: A320526 A193519 A268329 * A052978 A151023 A344501 Adjacent sequences:  A223092 A223093 A223094 * A223096 A223097 A223098 KEYWORD nonn AUTHOR N. J. A. Sloane, Mar 29 2013 EXTENSIONS Name clarified by Stéphane Legendre, Apr 09 2013 More terms from Stéphane Legendre, Apr 09 2013 STATUS approved

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Last modified December 7 09:15 EST 2021. Contains 349574 sequences. (Running on oeis4.)