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a(n) = mu(n) * 2^(n-1).
4

%I #9 Aug 12 2015 21:21:10

%S 1,-2,-4,0,-16,32,-64,0,0,512,-1024,0,-4096,8192,16384,0,-65536,0,

%T -262144,0,1048576,2097152,-4194304,0,0,33554432,0,0,-268435456,

%U -536870912,-1073741824,0,4294967296,8589934592,17179869184,0,-68719476736,137438953472,274877906944,0,-1099511627776

%N a(n) = mu(n) * 2^(n-1).

%C Row sums of A127512.

%C Appears to be the determinant of A156734 where the element in the lower right corner has been swapped with the element in the upper right corner. - _Mats Granvik_, Feb 14 2009

%F a(n)=A008683(n)*A000079(n-1). - _R. J. Mathar_, May 19 2007

%e a(5) = (-1)*16 = -16 since mu(5) = -1 and 2^4 = 16.

%p A127511 := proc(n) 2^(n-1)*numtheory[mobius](n) ; end: for n from 1 to 50 do printf("%d, ",A127511(n)) ; od ; # _R. J. Mathar_, May 19 2007

%Y Cf. A008683, A127512.

%K sign,easy

%O 1,2

%A _Gary W. Adamson_, Jan 17 2007

%E More terms from _R. J. Mathar_, May 19 2007