

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



EXAMPLE

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



KEYWORD

more,nonn


AUTHOR



EXTENSIONS

Moved conjectured terms a(11)a(30) to Comments.  N. J. A. Sloane, May 22 2014


STATUS

approved



