Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A057117
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A057117 Permutation of nonnegative integers obtained by mapping each forest of A000108[n] rooted binary plane trees from breadth-first to depth-first encoding. +0
18
0, 1, 2, 3, 4, 5, 7, 8, 6, 9, 10, 12, 13, 11, 17, 18, 21, 22, 20, 14, 15, 16, 19, 23, 24, 26, 27, 25, 31, 32, 35, 36, 34, 28, 29, 30, 33, 45, 46, 49, 50, 48, 58, 59, 63, 64, 62, 54, 55, 57, 61, 37, 38, 40, 41, 39, 44, 47, 42, 43, 56, 60, 51, 52, 53, 65, 66, 68, 69, 67, 73, 74 (list; graph; listen)
OFFSET

0,3

LINKS

A. Karttunen, Gatomorphisms (Includes the complete Scheme program for computing this sequence)

Index entries for sequences that are permutations of the natural numbers

MAPLE

a(n) = CatalanRankGlobal(btbf2df(binrev(A014486[n]), 0, 1)/2)

Maple procedure CatalanRank is adapted from the algorithm 3.23 of the CAGES book, see A014486

CatalanRank := proc(n, aa) local x, y, lo, a; a := binrev(aa); y := 0; lo := 0; for x from 1 to (2*n)-1 do lo := lo + (1-(a mod 2))*Mn(n, x, y+1); y := y - ((-1)^a); a := floor(a/2); od; RETURN((binomial(2*n, n)/(n+1))-(lo+1)); end;

CatalanRankGlobal := proc(a) local n; n := floor(binwidth(a)/2); RETURN(add((binomial(2*j, j)/(j+1)), j=0..(n-1))+CatalanRank(n, a)); end;

CROSSREFS

Restriction of the automorphism A072088 to the plane binary trees.

Add one to each term and "overlay" each successive subpermutation of A000108[n] terms and one obtains A038776. Inverse permutation is A057118.

Sequence in context: A130349 A130354 A082356 this_sequence A130941 A082360 A130392

Adjacent sequences: A057114 A057115 A057116 this_sequence A057118 A057119 A057120

KEYWORD

nonn

AUTHOR

Antti Karttunen Aug 11 2000

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified November 29 12:46 EST 2009. Contains 167659 sequences.


AT&T Labs Research