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Square array T(n,k), n >= 1, k >= 1, read by antidiagonals downwards, where T(n,k) = phi(k*n) / phi(k).
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%I #26 May 10 2024 09:26:01

%S 1,1,1,1,2,2,1,1,2,2,1,2,3,4,4,1,1,2,2,4,2,1,2,2,4,4,4,6,1,1,3,2,4,3,

%T 6,4,1,2,2,4,5,4,6,8,6,1,1,2,2,4,2,6,4,6,4,1,2,3,4,4,6,6,8,9,8,10,1,1,

%U 2,2,4,2,6,4,6,4,10,4,1,2,2,4,4,4,7,8,6,8,10,8,12,1,1,3,2,5,3,6,4,9,5,10,6,12,6

%N Square array T(n,k), n >= 1, k >= 1, read by antidiagonals downwards, where T(n,k) = phi(k*n) / phi(k).

%H Seiichi Manyama, <a href="/A372673/b372673.txt">Antidiagonals n = 1..140, flattened</a>

%e Square array T(n,k) begins:

%e 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, ...

%e 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, ...

%e 2, 2, 3, 2, 2, 3, 2, 2, 3, 2, 2, 3, 2, 2, 3, 2, 2, 3, ...

%e 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, ...

%e 4, 4, 4, 4, 5, 4, 4, 4, 4, 5, 4, 4, 4, 4, 5, 4, 4, 4, ...

%e 2, 4, 3, 4, 2, 6, 2, 4, 3, 4, 2, 6, 2, 4, 3, 4, 2, 6, ...

%e 6, 6, 6, 6, 6, 6, 7, 6, 6, 6, 6, 6, 6, 7, 6, 6, 6, 6, ...

%e 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, ...

%e 6, 6, 9, 6, 6, 9, 6, 6, 9, 6, 6, 9, 6, 6, 9, 6, 6, 9, ...

%o (PARI) T(n, k) = eulerphi(k*n)/eulerphi(k);

%Y Columns k=1..18 give: A000010, A062570, A195459, A062570, A359101, A372671, A359102, A062570, A195459, A372672, A372676, A372671, A372677, A372678, A372679, A062570, A372681, A372671.

%Y Main diagonal gives A000027.

%Y Cf. A005117, A372619.

%K nonn,tabl

%O 1,5

%A _Seiichi Manyama_, May 10 2024