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A108465 Table read by antidiagonals: T(n,k) (n>=2) = number of factorizations of (n,k) into pairs (i,j) with i,j>1. 1
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 3, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 3, 1, 3, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 1, 1, 3, 1, 3, 1, 4, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

2,13

COMMENTS

(a,b)*(x,y)=(a*x,b*y).

LINKS

Table of n, a(n) for n=2..106.

FORMULA

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)-1)*(zeta(t)-1).

EXAMPLE

1 1 1 1 1 ...

1 1 1 1 1 ...

1 1 2 1 2 ...

1 1 1 1 1 ...

1 1 2 1 3 ...

(8,6)=(4,3)*(2,2)=(4,2)*(2,3), so a(8,6)=3.

CROSSREFS

Cf. A108461. Columns 4, 6: A038548 (n>1), A032741. Main diagonal: A108466.

Sequence in context: A030575 A280940 A131789 * A069347 A161606 A300362

Adjacent sequences:  A108462 A108463 A108464 * A108466 A108467 A108468

KEYWORD

nonn,tabl

AUTHOR

Christian G. Bower, Jun 03 2005

STATUS

approved

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Last modified July 15 23:32 EDT 2020. Contains 335774 sequences. (Running on oeis4.)