|
| |
|
|
A093593
|
|
n! times sum of Farey fractions of order n.
|
|
2
| |
|
|
1, 3, 15, 84, 660, 4680, 47880, 463680, 5261760, 59875200, 858211200, 11256537600, 183697113600, 2833294464000, 47730114432000, 847372990464000, 17250840262656000, 329722245844992000, 7359528574734336000
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
LINKS
| Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics..
|
|
|
EXAMPLE
| Multiplication of nth-order positive Farey fractions by n! gives the integer sequence A002088(n), for n>=1. Arrange them in rows:
1
1 2
2 3 4 6
6 8 12 16 18 24
The sum over row 4 is a(4)=84.
|
|
|
MATHEMATICA
| Farey[n_] := Union[ Flatten[ Join[{0}, Table[a/b, {b, n}, {a, b}]]]]; Table[n!Plus @@ Farey[n], {n, 0, 20}] (from Robert G. Wilson v Apr 06 2004)
|
|
|
CROSSREFS
| Cf. A002088, A092824, A093594.
Sequence in context: A005809 A067122 A202336 * A011900 A118342 A084209
Adjacent sequences: A093590 A093591 A093592 * A093594 A093595 A093596
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Clark Kimberling (ck6(AT)evansville.edu), Apr 03 2004
|
|
|
EXTENSIONS
| More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Apr 06 2004
|
| |
|
|
