|
Search: id:A102448
|
|
|
| A102448 |
|
a(n) = number of ways to write n = k^2 * j, j <= k, GCD(k,j) = 1, j and k = positive integers. |
|
+0
5
|
|
| 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 2, 0, 0, 0, 0, 0
(list; graph; listen)
|
|
|
OFFSET
|
1,100
|
|
|
COMMENT
|
Sum_{n>0} a(n)/n = 2.
|
|
LINKS
|
Leroy Quet, Home Page (listed in lieu of email address)
|
|
EXAMPLE
|
a(18) = 1 because 18 = k^2 * j, j <= k, GCD(k,j)=1, in one way: k=3, j=2.
|
|
MATHEMATICA
|
t = Sort[ Flatten[ Table[ If[ GCD[j, k] == 1, k^2*j, {}], {k, 11}, {j, k}]]]; Table[ Count[t, n], {n, 105}] (from Robert G. Wilson v Feb 25 2005)
|
|
CROSSREFS
|
Cf. A102354, A104021, A104023, A104025.
Sequence in context: A118626 A062892 A118553 this_sequence A102683 A122840 A083919
Adjacent sequences: A102445 A102446 A102447 this_sequence A102449 A102450 A102451
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Leroy Quet, Feb 23 2005
|
|
EXTENSIONS
|
More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Feb 24 2005
|
|
|
Search completed in 0.002 seconds
|
