|
Search: id:A069074
|
|
| |
|
| 24, 120, 336, 720, 1320, 2184, 3360, 4896, 6840, 9240, 12144, 15600, 19656, 24360, 29760, 35904, 42840, 50616, 59280, 68880, 79464, 91080, 103776, 117600, 132600, 148824, 166320, 185136, 205320, 226920, 249984, 274560, 300696, 328440, 357840
(list; graph; listen)
|
|
|
OFFSET
|
0,1
|
|
|
COMMENT
|
sqrt(sum{x=0..n: 2*a(x)} + 1) = A056220(n+2) [From Doug Bell (bell.doug(AT)gmail.com), Mar 09 2009]
|
|
REFERENCES
|
T. J. I'a. Bromwich, Introduction to the Theory of Infinite Series, Macmillan, 2nd. ed. 1949, p. 190.
Konrad Knopp, Theory and application of infinite series, Dover, p. 269
|
|
LINKS
|
Konrad Knopp, Theorie und Anwendung der unendlichen Reihen, Berlin, J. Springer, 1922. (Original german edition of "Theory and Application of Infinite Series")
|
|
FORMULA
|
sum(n=0, inf, (-1)^n/a(n))=(Pi-3)/4.
|
|
CROSSREFS
|
Cf. A001844. A001844(n+1)^2 - a(n) and A001844(n+1)^2 + a(n) are both square numbers. [From Doug Bell (bell.doug(AT)gmail.com), Mar 08 2009]
Cf. A000466. a(n) = sum{k=0..2n+3: A000466(n+1) + 2k} which is the sum of 2n+4 consecutive odd integers starting at A000466(n+1). [From Doug Bell (bell.doug(AT)gmail.com), Mar 08 2009]
Sequence in context: A126411 A137799 A114200 this_sequence A059775 A052762 A099317
Adjacent sequences: A069071 A069072 A069073 this_sequence A069075 A069076 A069077
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 05 2002
|
|
|
Search completed in 0.002 seconds
|
