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Search: id:A066411
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| A066411 |
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Form a triangle with the numbers [0..n] on the base, where each number is the sum of the two below; a(n) = number of different possible values for the apex. |
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+0
3
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OFFSET
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0,3
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COMMENT
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a(n) = number of different possible sums of c_k * (n choose k) where the c_k are a permutation of 0 through n. - Joshua Zucker (joshua.zucker(AT)stanfordalumni.org), May 08 2006
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EXAMPLE
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For n = 2 we have three triangles:
..4.......5......3
.1,3.....2,3....2,1
0,1,2...0,2,1..2,0,1
with three different values for the apex, so a(2) = 3.
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CROSSREFS
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Cf. A062684, A062896.
Sequence in context: A100302 A023247 A027753 this_sequence A153410 A155778 A018978
Adjacent sequences: A066408 A066409 A066410 this_sequence A066412 A066413 A066414
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KEYWORD
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easy,more,nonn
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AUTHOR
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Naohiro Nomoto (n_nomoto(AT)yabumi.com), Dec 25 2001
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EXTENSIONS
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More terms from John W. Layman (layman(AT)math.vt.edu), Jan 07 2003
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