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A061855 Symmetric totally balanced binary sequences: those terms of A014486 which are equal to their reversed complement. 6
0, 2, 10, 12, 42, 52, 56, 170, 178, 204, 212, 232, 240, 682, 722, 738, 812, 852, 868, 920, 936, 976, 992, 2730, 2762, 2866, 2898, 2978, 3010, 3244, 3276, 3380, 3412, 3492, 3524, 3640, 3672, 3752, 3784, 3888, 3920, 4000, 4032, 10922, 11082, 11146 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

These encode symmetric (palindromic) structures in many of the Catalan families, e.g. mountain ranges, parenthesizations, unlabeled rooted plane trees.

LINKS

Table of n, a(n) for n=0..45.

A. Karttunen, Some notes on Catalan's Triangle

Index entries for sequences related to parenthesizing

FORMULA

a(0) = 0 and the rest with the Maple function map(op, [seq(PalTotBalBinSequences(j), j=1..10)]);

EXAMPLE

E.g. the 45th term 11146 is 10101110001010 in binary and can be interpreted as a parenthesization: ( )( )((( )))( )( )

MAPLE

map(op, [seq(PalTotBalBinSequences(j), j=1..10)]);

PalTotBalBinSequences := n -> map(ReflectBinSeq, NonDivingLatticeSequences(n), n);

CROSSREFS

Obtained by "reflecting" the terms of A061854. Cf. also A035928 (ReflectBinSeq), A061856, A069766.

Sequence in context: A075165 A209641 A209642 * A144145 A075170 A039571

Adjacent sequences:  A061852 A061853 A061854 * A061856 A061857 A061858

KEYWORD

nonn

AUTHOR

Antti Karttunen, May 11 2001

STATUS

approved

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Last modified October 17 16:18 EDT 2018. Contains 316285 sequences. (Running on oeis4.)