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A127470
Triangle equal to the matrix product A127466 * A051731.
2
1, 4, 2, 9, 0, 6, 16, 12, 0, 8, 25, 0, 0, 0, 20, 36, 18, 24, 0, 0, 12, 49, 0, 0, 0, 0, 0, 42, 64, 56, 0, 48, 0, 0, 0, 32, 81, 0, 72, 0, 0, 0, 0, 0, 54, 100, 50, 0, 0, 80, 0, 0, 0, 0, 40, 121, 0, 0, 0, 0, 0, 0, 0, 0, 0, 110, 144, 108, 96, 72, 0, 72, 0, 0, 0, 0, 0, 48
OFFSET
1,2
FORMULA
T(n,1) = n^2.
T(n,n) = n*phi(n) = A002618(n).
EXAMPLE
First few rows of the triangle are:
1;
4, 2;
9, 0, 6;
16, 12, 0, 8;
25, 0, 0, 0, 20;
36, 18, 24, 0, 0, 12;
49, 0, 0, 0, 0, 0, 42;
64, 56, 0, 48, 0, 0, 0, 32;
81, 0, 72, 0, 0, 0, 0, 0, 54;
...
MAPLE
A127470 := proc(n, k)
add( A127466(n, j)*A051731(j, k), j=k..n) ;
end proc: # R. J. Mathar, Sep 08 2013
CROSSREFS
Cf. A127466, A051731, A127469 (row sums), A061949.
Sequence in context: A190477 A143311 A016696 * A199449 A010649 A067721
KEYWORD
nonn,tabl
AUTHOR
Gary W. Adamson, Jan 15 2007
EXTENSIONS
Terms corrected by R. J. Mathar, Sep 08 2013
STATUS
approved