|
Search: id:A161901
|
|
|
| A161901 |
|
Array read by rows in which row n list the divisors of n, but if n is a square then the square root of n appears repeated. |
|
+0
10
|
|
| 1, 1, 1, 2, 1, 3, 1, 2, 2, 4, 1, 5, 1, 2, 3, 6, 1, 7, 1, 2, 4, 8, 1, 3, 3, 9, 1, 2, 5, 10, 1, 11, 1, 2, 3, 4, 6, 12, 1, 13, 1, 2, 7, 14, 1, 3, 5, 15, 1, 2, 4, 4, 8, 16, 1, 17, 1, 2, 3, 6, 9, 18, 1, 19, 1, 2, 4, 5, 10, 20, 1, 3, 7, 21
(list; graph; listen)
|
|
|
OFFSET
|
1,4
|
|
|
LINKS
|
O. E. Pol, Determinacion geometrica de los numeros primos y perfectos
O. E. Pol, Illustration: Divisors and pi(x)
|
|
EXAMPLE
|
Array begins:
....... 1,1;
....... 1,2;
....... 1,3;
..... 1,2,2,4;
....... 1,5;
..... 1,2,3,6;
....... 1,7;
..... 1,2,4,8;
..... 1,3,3,9;
..... 1,2,5,10;
....... 1,11;
... 1,2,3,4,6,12;
....... 1,13;
..... 1,2,7,14;
..... 1,3,5,15;
... 1,2,4,4,8,16;
|
|
CROSSREFS
|
Cf. A000005, A027750, A038548, A161841, A161842.
Sequence in context: A036989 A035197 A091948 this_sequence A102862 A029331 A037269
Adjacent sequences: A161898 A161899 A161900 this_sequence A161902 A161903 A161904
|
|
KEYWORD
|
easy,nonn,tabf
|
|
AUTHOR
|
Omar E. Pol (info(AT)polprimos.com), Jun 23 2009
|
|
EXTENSIONS
|
Keyword tabf added by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jun 28 2009
|
|
|
Search completed in 0.002 seconds
|
