|
| |
|
|
A128452
|
|
Least number k>n such that k^2 divides n^k - 1.
|
|
4
| |
|
|
4, 21, 6, 1555, 8, 889, 10, 111, 12, 253, 14, 2041, 16, 21, 18, 128583032925805678351, 20, 1432001198261, 22, 39, 24, 1081, 26, 55, 28, 171, 30, 279241, 32, 9641, 34, 1191, 36, 55, 38, 950123, 40, 1641, 42, 33661, 44, 32627169461820247, 46, 63, 48, 583223, 50
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 3,1
|
|
|
COMMENTS
| For prime p, p divides a(p+1). Quotients a(p+1)/p for prime p = A000040(n) are listed in A128456(n) which coincides with A128357(n) for n from 2 to 6.
a(n) divides n^(n-1) - 1.
|
|
|
FORMULA
| a(2n-1) = 2n.
|
|
|
CROSSREFS
| Cf. A128456, A128357, A128356, A127103, A127104, A127105, A127106, A127107, A127102, A127101, A127100, A127092, A128393, A128394, A128395, A128396, A128397, A128398, A128399, A128400, A128401, A128402, A128403, A128404.
Sequence in context: A146342 A103896 A083192 * A202450 A144292 A076943
Adjacent sequences: A128449 A128450 A128451 * A128453 A128454 A128455
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Alexander Adamchuk (alex(AT)kolmogorov.com), Mar 05 2007. Mar 09 2007
|
|
|
EXTENSIONS
| More terms from Alexander Adamchuk (alex(AT)kolmogorov.com), Mar 09 2007
Terms a(22) onward from Max Alekseyev (maxale(AT)gmail.com), May 05 2010
|
| |
|
|
