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Search: id:A139382
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| A139382 |
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Triangle read by rows, T(n,k) = (2^n-1) * T(n-1,k) + T(n-1,k-1). |
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+0
1
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| 1, 1, 1, 1, 4, 1, 1, 13, 11, 1, 1, 40, 90, 26, 1, 1, 121, 670, 480, 57, 1, 1, 364, 4811, 7870, 2247, 120, 1, 1, 1093, 34041, 122861, 77527, 9807, 247, 1
(list; table; graph; listen)
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OFFSET
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1,5
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COMMENT
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Row sums = A135922 starting with offset 1: (1, 2, 6, 26, 158, 1330,...).
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FORMULA
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Triangle read by rows, T(n,k) = (2^n-1) * T(n-1,k) + (T(n-1,k-1). Let X = an infinite bidiagonal matrix with (1,3,7,15,31...) in the main diagonal and (1,1,1,...) in the subdiagonal. n-th row of the triangle = X^n * [1,0,0,0,...].
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EXAMPLE
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First few rows of the triangle are:
1;
1, 1;
1, 4, 1;
1, 13, 11, 1;
1, 40, 90, 26, 1;
1, 121, 670, 480, 57, 1;
...
a(13) = T(5,3) = 90 = (2^3 - 1)* T(4,3) + T(4,2) = 7*11 + 13.
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CROSSREFS
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Cf. A135922.
Sequence in context: A039755 A047874 A080248 this_sequence A157180 A146956 A152613
Adjacent sequences: A139379 A139380 A139381 this_sequence A139383 A139384 A139385
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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), Apr 16 2008
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