|
Search: id:A110754
|
|
|
| A110754 |
|
a(n) = tau(N), where N = the number obtained as a concatenation of 8712 with itself n times and tau(n) = number of divisors of n. |
|
+0
2
|
|
| 36, 144, 768, 576, 1152, 6144, 2304, 18432, 15360, 18432, 12288, 49152, 4608, 36864, 6291456, 294912, 9216, 983040, 576, 294912, 18874368, 196608
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
8712 has the property that any number of concatenation of it with self and the digit reversal have same prime divisors.
|
|
FORMULA
|
a(n)=A000005[8712*sum_{i=0..n-1} 10^(4i)] . - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 17 2007
|
|
EXAMPLE
|
a(2) =tau(87128712) = 144.
|
|
MAPLE
|
A110754 := proc(n) local pow8712, i ; pow8712 := 8712*add(10^(4*i), i=0..n-1) ; numtheory[tau](pow8712) ; end: seq(A110754(n), n=1..22) ; - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 17 2007
|
|
CROSSREFS
|
Cf. A110751, A110752, A110753.
Sequence in context: A119767 A016910 A005017 this_sequence A154711 A162992 A037072
Adjacent sequences: A110751 A110752 A110753 this_sequence A110755 A110756 A110757
|
|
KEYWORD
|
base,nonn
|
|
AUTHOR
|
Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Aug 11 2005
|
|
EXTENSIONS
|
More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 17 2007
|
|
|
Search completed in 0.002 seconds
|
