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A067689 Inverse of determinant of n X n matrix whose (i,j)-th element is 1/(i+j). 9
2, 72, 43200, 423360000, 67212633600000, 172153600393420800000, 7097063852481244869427200000, 4702142622508202833251304734720000000, 50019370356486058711268515056654483456000000000 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

REFERENCES

Jerry Glynn and Theodore Gray, "The Beginner's Guide to Mathematica Version 4," Cambridge University Press, Cambridge UK, 2000, page 76.

LINKS

T. D. Noe, Table of n, a(n) for n=1..25

FORMULA

A067689 = A005249 * A000984 - Sharon Sela (sharonsela(AT)hotmail.com), Apr 18 2002.

EXAMPLE

The matrix begins:

1/2 1/3 1/4 1/5 1/6 1/7 1/8 ...

1/3 1/4 1/5 1/6 1/7 1/8 1/9 ...

1/4 1/5 1/6 1/7 1/8 1/9 1/10 ...

1/5 1/6 1/7 1/8 1/9 1/10 1/11 ...

1/6 1/7 1/8 1/9 1/10 1/11 1/12 ...

1/7 1/8 1/9 1/10 1/11 1/12 1/13 ...

MATHEMATICA

Table[ 1 / Det[ Table[ 1 / (i + j), {i, 1, n}, {j, 1, n} ]], {n, 1, 10} ]

CROSSREFS

Cf. A005249, A000984, A060739. See A005249 for a formula.

Sequence in context: A123072 A099681 A062082 * A079478 A036899 A041647

Adjacent sequences:  A067686 A067687 A067688 * A067690 A067691 A067692

KEYWORD

nonn,nice

AUTHOR

Robert G. Wilson v (rgwv(AT)rgwv.com), Feb 04 2002

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Last modified February 15 10:06 EST 2012. Contains 205763 sequences.