

A127466


Triangle read by rows: A054525 * A127481 as infinite lower triangular matrices.


5



1, 2, 2, 3, 0, 6, 4, 4, 0, 8, 5, 0, 0, 0, 20, 6, 6, 12, 0, 0, 12, 7, 0, 0, 0, 0, 0, 42, 8, 8, 0, 16, 0, 0, 0, 32, 9, 0, 18, 0, 0, 0, 0, 0, 54, 10, 10, 0, 0, 40, 0, 0, 0, 0, 40
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OFFSET

1,2


COMMENTS

Mobius transform of A127481.


LINKS

Table of n, a(n) for n=1..55.


FORMULA

Sum_{k=1..n} T(n,k) = n^2.
T(n,n) = A002618(n) = n*phi(n).


EXAMPLE

First few rows of the triangle are:
1;
2, 2;
3, 0, 6;
4, 4, 0, 8;
5, 0, 0, 0, 20;
6, 6, 12, 0, 0, 12;
7, 0, 0, 0, 0, 0, 42;
8, 8, 0, 16, 0, 0, 0, 32;
...


MAPLE

A127466 := proc(n, k)
add( A054525(n, j)*A127481(j, k), j=k..n) ;
end proc: # R. J. Mathar, Sep 06 2013


CROSSREFS

Cf. A054522, A127093, A062952, A002618.
Cf. A127093, A127481, A054525.
Sequence in context: A330925 A191361 A199784 * A342314 A099118 A320999
Adjacent sequences: A127463 A127464 A127465 * A127467 A127468 A127469


KEYWORD

nonn,tabl


AUTHOR

Gary W. Adamson, Jan 15 2007


EXTENSIONS

Edited by N. J. A. Sloane at the suggestion of Andrew S. Plewe, Aug 23 2007


STATUS

approved



