|
Search: id:A130553
|
|
|
| A130553 |
|
Numerators of partial sums for a series for 2*Pi*sqrt(3)/9. |
|
+0
2
|
|
| 1, 7, 6, 169, 1523, 133, 72623, 87149, 823077, 15638477, 46915441, 13834041, 224803169, 6936783521, 5587964507, 4157445593923, 12472336782289, 170187831339, 71785227258967, 153825486983593, 4905323862699739
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
COMMENT
|
Denominators are given in A130554.
The rational sequence r(n):=2*sum(1/(j*binomial(2*j,j)),j=1..n), n>=1, tends, in the limit n->infinity, to 2*Pi*sqrt(3)/9, which is approximately 1.209199577.
|
|
REFERENCES
|
L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 89, Exercise.
|
|
LINKS
|
W. Lang, Rationals and limit.
|
|
FORMULA
|
a(n)=numerator(r(n)), n>=1, with the rationals r(n) defined above and taken in lowest terms.
|
|
EXAMPLE
|
Rationals r(n): [1, 7/6, 6/5, 169/140, 1523/1260, 133/110, 72623/60060,...].
|
|
CROSSREFS
|
Adjacent sequences: A130550 A130551 A130552 this_sequence A130554 A130555 A130556
Sequence in context: A073112 A070425 A038272 this_sequence A002394 A105167 A109938
|
|
KEYWORD
|
nonn,frac,easy
|
|
AUTHOR
|
Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de) Jul 13 2007
|
|
|
Search completed in 0.002 seconds
|
