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A127448 Triangle T(n,k) read by rows: matrix product A054525 * A127648. 3

%I #10 Jan 07 2015 10:03:08

%S 1,-1,2,-1,0,3,0,-2,0,4,-1,0,0,0,5,1,-2,-3,0,0,6,-1,0,0,0,0,0,7,0,0,0,

%T -4,0,0,0,8,0,0,-3,0,0,0,0,0,9,1,-2,0,0,-5,0,0,0,0,10,-1,0,0,0,0,0,0,

%U 0,0,0,11,0,2,0,-4,0,-6,0,0,0,0,0,12,-1,0,0,0,0,0,0,0,0,0,0,0,13,1,-2,0,0,0,0,-7,0,0,0,0,0,0

%N Triangle T(n,k) read by rows: matrix product A054525 * A127648.

%F T(n,k) = sum _{j=k..n} A054525(n,j)*A127648(j,k) = k*A054525(n,k).

%F sum_{k=1..n} T(n,k) = A000010(n) (row sums).

%F T(n,1) = A008683(n).

%e First few rows of the triangle are;

%e 1;

%e -1, 2;

%e -1, 0, 3;

%e 0, -2, 0, 4;

%e -1, 0, 0, 0, 5;

%e 1, -2, -3, 0, 0, 6;

%e -1, 0, 0, 0, 0, 0, 7;

%e 0, 0, 0, -4, 0, 0, 0, 8;

%e 0, 0, -3, 0, 0, 0, 0, 0, 9;

%e 1, -2, 0, 0,-5, 0, 0, 0, 0, 10;

%e ...

%p A127648 := proc(n,k) if n = k then n; else 0 ; fi; end:

%p A054525 := proc(n,k) if k = n then 1; elif n mod k = 0 then numtheory[mobius](n/k) ; else 0 ; fi; end:

%p A127448 := proc(n,k) add( A054525(n,j)*A127648(j,k), j=k..n) ; end: seq(seq( A127448(n,k),k=1..n),n=1..15) ;

%Y Cf. A000010, A008683, A051731.

%K tabl,sign,easy

%O 1,3

%A _Gary W. Adamson_, Jan 14 2007

%E Converted comments to formulas, extended - _R. J. Mathar_, Sep 11 2009

%E Corrected A-number typo in a formula - _R. J. Mathar_, Sep 17 2009

%E Corrected last example line by _John Mason_, Jan 07 2015

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Last modified March 29 10:59 EDT 2024. Contains 371277 sequences. (Running on oeis4.)