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Search: id:A123081
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| A123081 |
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Infinite square array read by antidiagonals: T(n,k) = Bell(n+k) = A000110(n+k), n >= 0, k >= 0. |
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1
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| 1, 1, 1, 2, 2, 2, 5, 5, 5, 5, 15, 15, 15, 15, 15, 52, 52, 52, 52, 52, 52, 203, 203, 203, 203, 203, 203, 203, 877, 877, 877, 877, 877, 877, 877, 877
(list; table; graph; listen)
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OFFSET
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0,4
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COMMENT
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Alternatively, triangle read by rows in which row n (n >= 0) conatins A000110(n) repeated n+1 times.
Row sums = A052887: 1, 2, 6, 20, 75, 312,... A127568 = Q * M n-th row is comprised of n+1 terms of A000110(n).
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REFERENCES
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W. F. Lunnon et al., Arithmetic properties of Bell numbers to a composite modulus I, Acta Arith., 35 (1979), 1-16. [From N. J. A. Sloane (njas(AT)research.att.com), Feb 07 2009]
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FORMULA
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M * Q, as infinite lower triangular matrices; M = the Bell sequence, A000110 in the main diagonal and the rest zeros. Q = (1; 1, 1; 1, 1, 1;...)
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EXAMPLE
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First few rows of the triangle are:
1;
1, 1;
2, 2, 2;
5, 5, 5, 5;
15, 15, 15, 15;
52, 52, 52, 52, 52;
203, 203, 203, 203, 203, 203;
...
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CROSSREFS
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Cf. A127568, A052887, A000110.
Sequence in context: A098101 A105960 A081290 this_sequence A020917 A035643 A163946
Adjacent sequences: A123078 A123079 A123080 this_sequence A123082 A123083 A123084
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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), Jan 19 2007
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EXTENSIONS
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Edited by N. J. A. Sloane (njas(AT)research.att.com), Feb 07 2009
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