|
| |
|
|
A086565
|
|
Smallest k such that (10^k - 1)/9 has n distinct prime divisors. Or a(n)= smallest value of k such that A000042(k) has exactly n distinct prime divisors.
|
|
0
| |
|
|
1, 2, 3, 9, 8, 6, 15, 12, 18, 45, 24, 32, 54, 30, 42, 64, 102, 72, 108, 154, 60, 84, 96, 140, 126, 200, 120, 204
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
COMMENTS
| a(20) = 60; all other subsequent terms are > 70. - David Wasserman (wasserma(AT)spawar.navy.mil), Mar 28 2005
|
|
|
CROSSREFS
| Cf. A000042.
Sequence in context: A205860 A021421 A152812 * A008291 A122665 A133066
Adjacent sequences: A086562 A086563 A086564 * A086566 A086567 A086568
|
|
|
KEYWORD
| more,nonn
|
|
|
AUTHOR
| Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Aug 31 2003
|
|
|
EXTENSIONS
| Corrected and extended by Sascha Kurz (sascha.kurz(AT)uni-bayreuth.de), Sep 22 2003
a(12)-a(15) from David Wasserman (wasserma(AT)spawar.navy.mil), Mar 28 2005
a(16)-a(27) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Nov 17 2008
|
| |
|
|
