|
| |
|
|
A090880
|
|
Suppose n=(p1^e1)(p2^e2)... where p1,p2,... are the prime numbers and e1,e2,... are nonnegative integers. Then a(n) = e1 + (e2)*3 + (e3)*9 + (e4)*27 + ... + (ek)*(3^(k-1)) + ...
|
|
6
| |
|
|
0, 1, 3, 2, 9, 4, 27, 3, 6, 10, 81, 5, 243, 28, 12, 4, 729, 7, 2187, 11, 30, 82, 6561, 6, 18, 244, 9, 29, 19683, 13, 59049, 5, 84, 730, 36, 8, 177147, 2188, 246, 12, 531441, 31, 1594323, 83, 15, 6562, 4782969, 7, 54, 19, 732, 245, 14348907, 10, 90, 30, 2190
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,3
|
|
|
COMMENTS
| Replace "3" with "x" and extend the definition of a to positive rationals and a becomes an isomorphism between positive rationals under multiplication and polynomials over Z under addition. This remark generalizes A001222, A048675 and A054841: evaluate said polynomial at x=1, x=2 and x=10, respectively.
|
|
|
REFERENCES
| Joseph J. Rotman, The Theory of Groups: An Introduction, 2nd ed. Boston: Allyn and Bacon, Inc. 1973. Page 9, problem 1.26.
|
|
|
LINKS
| Sam Alexander, Post to sci.math.
|
|
|
CROSSREFS
| Cf. A001222, A048675, A054841, A090881, A090882, A090883, A090884.
Sequence in context: A090639 A178774 A182652 * A188926 A193980 A194001
Adjacent sequences: A090877 A090878 A090879 * A090881 A090882 A090883
|
|
|
KEYWORD
| easy,nonn
|
|
|
AUTHOR
| Sam Alexander (amnalexander(AT)yahoo.com), Dec 12 2003
|
|
|
EXTENSIONS
| More terms from Ray Chandler (rayjchandler(AT)sbcglobal.net), Dec 20 2003
|
| |
|
|
