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A083942 Positions of breadth-first-wise encodings (A002542) of the complete binary trees (A084107) in A014486. +0
2
0, 1, 8, 625, 13402696, 19720133460129649, 126747521841153485025455279433135688, 15141471069096667541622192498608408980462133134430650704600552060872705905 (list; graph; listen)
OFFSET

0,3

COMMENT

Conjecture: a(n) = Sum [ CatalanNumber[ k ], {k, 1, 2^n-1} ] = Sum[ (2k)!/(k!(k+1)!), {k, 1, 2^n-1} ]. - Alexander Adamchuk (alex(AT)kolmogorov.com), Nov 10 2007

LINKS

Alexander Adamchuk (alex(AT)kolmogorov.com), Nov 10 2007, Table of n, a(n) for n = 0..11

Eric Weisstein, Link to a section of The World of Mathematics, Catalan Number.

FORMULA

a(n) = A080300(A002542(n)). [Provided that 2^((2^n)-1)*((2^((2^n)-1))-1) is indeed the formula for A002542.]

Conjecture: a(n) = Sum[ Binomial[ 2k, k ]/(k+1), {k, 1, 2^n-1} ] = Sum [ CatalanNumber[ k ], {k, 1, 2^n-1} ] = Sum[ (2k)!/(k!(k+1)!), {k, 1, 2^n-1} ]. a(n) = A014138(2^n-2) for n>0. - Alexander Adamchuk (alex(AT)kolmogorov.com), Nov 10 2007

MATHEMATICA

Table[ Sum[ Binomial[ 2k, k ]/(k+1), {k, 1, 2^n-1} ], {n, 0, 10} ] - Alexander Adamchuk (alex(AT)kolmogorov.com), Nov 10 2007

CROSSREFS

a(n) = A057118(A084108(n)).

Cf. A014138 = Partial sums of Catalan numbers (starting 1, 2, 5, ..., cf. A000108). Cf. A000108 = Catalan Numbers.

Adjacent sequences: A083939 A083940 A083941 this_sequence A083943 A083944 A083945

Sequence in context: A015023 A090923 A080320 this_sequence A027877 A015106 A099126

KEYWORD

nonn

AUTHOR

Antti Karttunen (MyFirstname.MySurname(AT)iki.fi) May 13 2003

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Last modified October 10 20:39 EDT 2008. Contains 144831 sequences.


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