

A127476


Triangle T(n,k) = sum_{j=k..n, gcd(n,j)=1, kj} phi(k).


0



1, 1, 0, 2, 1, 0, 2, 0, 2, 0, 4, 2, 2, 2, 0, 2, 0, 0, 0, 4, 0, 6, 3, 4, 2, 4, 2, 0, 4, 0, 2, 0, 4, 0, 6, 0, 6, 3, 0, 4, 4, 0, 6, 4, 0, 4, 0, 4, 0, 0, 0, 6, 0, 6, 0, 10, 5, 6, 4, 8, 2, 6, 4, 6, 4, 0, 4, 0, 0, 0, 4, 0, 6, 0, 0, 0, 10, 0
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OFFSET

1,4


LINKS

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


FORMULA

T(n,k) = sum_{j=k..n} A054521(n,j) * A054522(j,k), product of the two infinite lower triangular matrices.
T(n,1) = A000010(n).


EXAMPLE

First few rows of the triangle are:
1;
1, 0;
2, 1, 0;
2, 0, 2, 0;
4, 2, 2, 2, 0;
2, 0, 0, 0, 4, 0;
6, 3, 4, 2, 4, 2, 0;
4, 0, 2, 0, 4, 0, 6, 0;
...


CROSSREFS

Cf. A054521, A054522, A023896 (row sums), A000010.
Sequence in context: A244553 A231167 A194313 * A140397 A120614 A287516
Adjacent sequences: A127473 A127474 A127475 * A127477 A127478 A127479


KEYWORD

nonn,tabl


AUTHOR

Gary W. Adamson, Jan 15 2007


STATUS

approved



