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Number of elements in the Redheffer matrix that contribute to the Moebius function.
0

%I #7 May 22 2014 23:29:40

%S 1,2,3,6,5,10,7,13,11,14

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

%C 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]

%e Contribution from _Mats Granvik_, Dec 21 2008: (Start)

%e The contributing elements for a(8) are:

%e 0,0,0,0,0,0,0,1

%e 1,1,0,0,0,0,0,0

%e 0,0,1,0,0,0,0,0

%e 1,1,0,1,0,0,0,0

%e 0,0,0,0,1,0,0,0

%e 0,0,0,0,0,1,0,0

%e 0,0,0,0,0,0,1,0

%e 1,1,0,1,0,0,0,0

%e 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)

%Y Cf. A008683, A143104.

%K more,nonn

%O 1,2

%A _Mats Granvik_, Oct 02 2008

%E a(9)-a(10) from _Mats Granvik_, Oct 05 2008

%E Moved conjectured terms a(11)-a(30) to Comments. - _N. J. A. Sloane_, May 22 2014