|
Search: id:A117430
|
|
| |
|
| 3, -1, 0, -2, 1, 2, -2, -2, -2, -3, 2, 2, -2, -4, 4, 2, -8, -6, -2, -3, -2
(list; graph; listen)
|
|
|
OFFSET
|
0,1
|
|
|
COMMENT
|
Distance from 5^n to the nearest semiprime. See also: A117416 Semiprime nearest to 3^n. A117405 Semiprime nearest to 2^n. A117387 Prime nearest to 2^n.
|
|
FORMULA
|
a(n) = Integer k such that 5^n + k = A117429(n). a(n) = A117429(n) - 5^n. a(n) = Min{k such that A001358(i) + k = 5^n}.
|
|
EXAMPLE
|
a(0) = 3 because 5^0 + 3 = 4 = A001358(1) and no semiprime is closer to 5^0.
a(1) = -1 because 5^1 - 1 = 4 = A001358(1) and no semiprime is closer to 5^1.
a(2) = 0 because 5^2 + 0 = 25 = A001358(9), no semiprime is closer to 5^2 [this is the only 0 element].
a(3) = -2 because 5^3 - 2 = 123 = 3 * 41 = A00135842), no semiprime is closer.
a(4) = 1 because 5^4 + 1 = 626 = 2 * 313, no semiprime is closer.
a(5) = 2 because 5^5 + 2 = 3127 = 53 * 59, no semiprime is closer.
|
|
CROSSREFS
|
Cf. A000079, A001358, A117387, A117405, A117406, A117416, A117429.
Sequence in context: A166408 A128618 A101548 this_sequence A143676 A002726 A119734
Adjacent sequences: A117427 A117428 A117429 this_sequence A117431 A117432 A117433
|
|
KEYWORD
|
easy,sign,less
|
|
AUTHOR
|
Jonathan Vos Post (jvospost3(AT)gmail.com), Mar 14 2006
|
|
|
Search completed in 0.002 seconds
|
