|
Search: id:A152761
|
|
| |
|
| 1, 1, 3, 6, 24, 96, 336, 672, 3024, 9072, 35280, 120960, 483840, 1874880, 10108800, 20217600, 107827200, 398131200, 1919877120, 6051594240, 24710676480, 86487367680, 339771801600, 1141066967040, 4122564526080, 16784726999040
(list; graph; listen)
|
|
|
OFFSET
|
0,3
|
|
|
FORMULA
|
a(n) = sigma(A000108(n)) = A000203(A000108(n)).
a(n)=A152762(n)+A000108(n). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 08 2009]
|
|
MAPLE
|
with(numtheory): seq(sigma(binomial(2*n, n)/(n+1)), n = 0 .. 25); [From Emeric Deutsch (deutsch(AT)duke.poly.edu), Jan 10 2009]
A000108 := proc(n) binomial(2*n, n)/(n+1) ; end: A000203 := proc(n) numtheory[sigma](n) ; end: A152761 := proc(n) A000203(A000108(n)) ; end: for n from 0 to 30 do printf("%d, ", A152761(n)) ; od: [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 08 2009]
|
|
CROSSREFS
|
Cf. A000108, A000203.
Sequence in context: A148656 A054718 A132390 this_sequence A109155 A081072 A000717
Adjacent sequences: A152758 A152759 A152760 this_sequence A152762 A152763 A152764
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Omar E. Pol (info(AT)polprimos.com), Dec 14 2008
|
|
EXTENSIONS
|
Extended by R. J. Mathar (mathar(AT)strw.leidenuniv.nl) and Emeric Deutsch (deutsch(AT)duke.poly.edu), Jan 08 2009
|
|
|
Search completed in 0.002 seconds
|
