|
| |
|
|
A076444
|
|
Smallest powerful number (definition 1) such that a(n)+n is also powerful.
|
|
4
| |
|
|
8, 25, 1, 4, 4, 214369, 1, 1, 16, 2187, 16, 4, 36, 30459361, 1, 9, 8, 9, 8, 16, 4, 27, 4, 1, 100, 1, 9, 4, 196, 6859, 1, 4, 16, 899236854927, 1, 36, 27, 1331, 25, 9, 8, 518436000625, 200, 64, 4, 243, 25, 1, 32, 625, 49, 144, 72, 27, 9, 8, 64, 109503, 49, 4, 64, 3025, 1, 8, 16
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
COMMENTS
| All terms n>0 exist (see Guy).
Sister sequence of a(n)+n given by A103952.
a(110) > 10^22. - Donovan Johnson, Nov 19 2011
|
|
|
REFERENCES
| R. K. Guy, Unsolved Problems in Number Theory, B16
|
|
|
LINKS
| Donovan Johnson, Table of n, a(n) for n = 1..109
Eric Weisstein's World of Mathematics, Powerful numbers
|
|
|
EXAMPLE
| 214369=463^2 and 214375=5^4*7^3 are the smallest pair of powerful numbers differing by 6, so a(6)=214369.
|
|
|
CROSSREFS
| Cf. A001694, A103952, A103953, A103954.
Sequence in context: A166483 A132586 A103953 * A023056 A103954 A200838
Adjacent sequences: A076441 A076442 A076443 * A076445 A076446 A076447
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Jud McCranie (JudMcCr(AT)BellSouth.net), Oct 13 2002
|
|
|
EXTENSIONS
| More terms from Max Alekseyev (maxale(AT)gmail.com), Feb 22 2005
|
| |
|
|
