

A145110


Number of elements in the Redheffer matrix that contribute to the Moebius function.


0




OFFSET

1,2


COMMENTS

a(11) to a(30) are conjectured to be 11, 23, 13, 18, 19, 25, 17, 29, 19, 30, 26, 26, 23, 45, 27, 30, 32, 39, 29, 48. [From Mats Granvik, Dec 21 2008]


LINKS

Table of n, a(n) for n=1..10.


EXAMPLE

Contribution from Mats Granvik, Dec 21 2008: (Start)
The contributing elements for a(8) are:
0,0,0,0,0,0,0,1
1,1,0,0,0,0,0,0
0,0,1,0,0,0,0,0
1,1,0,1,0,0,0,0
0,0,0,0,1,0,0,0
0,0,0,0,0,1,0,0
0,0,0,0,0,0,1,0
1,1,0,1,0,0,0,0
where rows 8, 4 and 2 are included because they are divisors of 8. The sum of this array is 13, therefore a(8) = 13. (End)


CROSSREFS

Cf. A008683, A143104.
Sequence in context: A272214 A080029 A091239 * A257405 A043547 A064919
Adjacent sequences: A145107 A145108 A145109 * A145111 A145112 A145113


KEYWORD

more,nonn


AUTHOR

Mats Granvik, Oct 02 2008


EXTENSIONS

a(9)a(10) from Mats Granvik, Oct 05 2008
Moved conjectured terms a(11)a(30) to Comments.  N. J. A. Sloane, May 22 2014


STATUS

approved



