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Search: id:A124929
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| A124929 |
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Triangle read by rows: T(n,k)=(2^k-1)binom(n-1,k-1) (1<=k<=n). |
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3
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| 1, 1, 3, 1, 6, 7, 1, 9, 21, 15, 1, 12, 42, 60, 31, 1, 15, 70, 150, 155, 63, 1, 18, 105, 300, 465, 378, 127, 1, 21, 147, 525, 1085, 1323, 889, 255, 1, 24, 196, 840, 2170, 3528, 3556, 2040, 511, 1, 27, 252, 1260, 3906, 7938, 10668, 9180, 4599, 1023, 1, 30, 315, 1800
(list; table; graph; listen)
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OFFSET
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1,3
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COMMENT
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Row sums = 2*(3^n) - 2^n = A027649: (1, 4, 14, 46, 146...).
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EXAMPLE
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First few rows of the triangle are:
1;
1, 3;
1, 6, 7;
1, 9, 21, 15;
1, 12, 42, 60, 31;
1, 15, 70, 150, 155, 127;
...
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MAPLE
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T:=(n, k)->(2^k-1)*binomial(n-1, k-1): for n from 1 to 11 do seq(T(n, k), k=1..n) od; # yields sequence in triangular form
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CROSSREFS
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Cf. A027649.
Sequence in context: A116412 A089511 A112692 this_sequence A103407 A074475 A144877
Adjacent sequences: A124926 A124927 A124928 this_sequence A124930 A124931 A124932
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KEYWORD
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nonn,tabl
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AUTHOR
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Gary W. Adamson (qntmpkt(AT)yahoo.com), Nov 12 2006
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EXTENSIONS
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Edited by N. J. A. Sloane (njas(AT)research.att.com), Nov 29 2006
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