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Search: id:A108455
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| A108455 |
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Table read by antidiagonals: T(n,k) = number of factorizations of (n,k) into pairs (i,j) with i>1, j>=1. |
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+0
4
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| 1, 0, 1, 0, 1, 1, 0, 1, 1, 2, 0, 1, 1, 2, 1, 0, 1, 1, 2, 1, 2, 0, 1, 1, 3, 1, 3, 1, 0, 1, 1, 2, 1, 3, 1, 3, 0, 1, 1, 3, 1, 4, 1, 4, 2, 0, 1, 1, 2, 1, 3, 1, 4, 2, 2, 0, 1, 1, 3, 1, 5, 1, 6, 2, 3, 1, 0, 1, 1, 3, 1, 3, 1, 4, 3, 3, 1, 4, 0, 1, 1, 3, 1, 5, 1, 7, 2, 4, 1, 7, 1, 0, 1, 1, 2, 1, 4, 1, 4, 3, 3, 1, 7, 1, 2
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OFFSET
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1,10
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COMMENT
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(a,b)*(x,y)=(a*x,b*y); unit is (1,1).
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FORMULA
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Dirichlet g.f.: A(s, t) = exp(B(s, t)/1 + B(2*s, 2*t)/2 + B(3*s, 3*t)/3 + ...) where B(s, t) = zeta(s)*(zeta(t)-1).
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EXAMPLE
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1 0 0 0 0 ...
1 1 1 1 1 ...
1 1 1 1 1 ...
2 2 2 3 2 ...
1 1 1 1 1 ...
(6,4)=(3,4)*(2,1)=(3,1)*(2,4)=(3,2)*(2,2), so a(6,4)=4.
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CROSSREFS
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Cf. A108461. Column 1: A001055. Main diagonal: A051707.
Sequence in context: A088432 A071466 A155041 this_sequence A117468 A116374 A025911
Adjacent sequences: A108452 A108453 A108454 this_sequence A108456 A108457 A108458
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KEYWORD
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nonn,tabl
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AUTHOR
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Christian G. Bower (bowerc(AT)usa.net), Jun 03 2005
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