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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 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..78.

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

Adjacent sequences:  A127467 A127468 A127469 * A127471 A127472 A127473

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, Jan 15 2007

EXTENSIONS

Terms corrected by R. J. Mathar, Sep 08 2013

STATUS

approved

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Last modified May 26 00:32 EDT 2020. Contains 334613 sequences. (Running on oeis4.)