The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A223093 Number of foldings of n labeled stamps in which leaf 1 is inwards and leaf n outwards (or leaf 1 outwards and leaf n inwards). 3
 0, 0, 2, 4, 16, 38, 132, 342, 1144, 3134, 10370, 29526, 97458, 285458, 942920, 2822310, 9341008, 28440970, 94358558, 291294678, 968853072, 3025232480, 10086634316, 31797822936, 106265437078, 337731551446, 1131117792978, 3620119437762, 12148796744234, 39118879440938 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 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. Index entries for sequences obtained by enumerating foldings FORMULA a(n) = A000682(n+1) - A077014(n). - Andrew Howroyd, Dec 06 2015 A217310(n) = 2*a(n) if n is odd and A217310(n) = a(n) if n is even. - Stéphane Legendre, Jan 09 2014 MATHEMATICA A000682 = Cases[Import["https://oeis.org/A000682/b000682.txt", "Table"], {_, _}][[All, 2]]; A077014 = Cases[Import["https://oeis.org/A077014/b077014.txt", "Table"], {_, _}][[All, 2]]; a[n_] := A000682[[n + 1]] - A077014[[n + 1]]; Array[a, 30] (* Jean-François Alcover, Sep 07 2019, after Andrew Howroyd *) CROSSREFS Sequence in context: A051861 A296297 A290265 * A333022 A048222 A192890 Adjacent sequences: A223090 A223091 A223092 * A223094 A223095 A223096 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 12 15:11 EDT 2024. Contains 375113 sequences. (Running on oeis4.)