|
Search: id:A116882
|
|
|
| A116882 |
|
A number n is included if (highest odd divisor of n)^2 <= n. |
|
+0
2
|
|
| 1, 2, 4, 8, 12, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 208, 224, 240, 256, 288, 320, 352, 384, 416, 448, 480, 512, 544, 576, 608, 640, 672, 704, 736, 768, 800, 832, 864, 896, 928, 960, 992, 1024, 1088, 1152, 1216, 1280, 1344, 1408
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
COMMENT
|
Also n is included if (and only if ) the greatest power of 2 dividing n is >= the highest odd divisor of n. All terms of the sequence are even besides the 1.
|
|
EXAMPLE
|
40 = 8 * 5, where 8 is highest power of 2 dividing 40, and 5 is the highest odd dividing 40. 8 is >= 5 (and, uncoincidently, 5^2 <= 40), so 40 is in the sequence.
|
|
MATHEMATICA
|
f[n_] := Select[Divisors[n], OddQ[ # ] &][[ -1]]; Insert[Select[Range[2, 1500], 2^FactorInteger[ # ][[1]][[2]] > f[ # ] &], 1, 1] - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Apr 10 2006
|
|
CROSSREFS
|
Cf. A116883, A000265, A006519.
Adjacent sequences: A116879 A116880 A116881 this_sequence A116883 A116884 A116885
Sequence in context: A118030 A047836 A070173 this_sequence A069519 A087980 A052184
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Leroy Quet (qq-quet(AT)mindspring.com), Feb 24 2006
|
|
EXTENSIONS
|
More terms from Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Apr 10 2006
|
|
|
Search completed in 0.002 seconds
|
