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 A308674 Square array A(n,k), n >= 1, k >= 0, read by antidiagonals, where A(n,k) is Sum_{d|n} d^(d^k). 4

%I

%S 1,1,3,1,5,4,1,17,28,7,1,257,19684,261,6,1,65537,7625597484988,

%T 4294967313,3126,12,1,4294967297,

%U 443426488243037769948249630619149892804,340282366920938463463374607431768211713,298023223876953126,46688,8

%N Square array A(n,k), n >= 1, k >= 0, read by antidiagonals, where A(n,k) is Sum_{d|n} d^(d^k).

%H Seiichi Manyama, <a href="/A308674/b308674.txt">Antidiagonals n = 1..9, flattened</a>

%F L.g.f. of column k: -log(Product_{j>=1} (1 - x^j)^(j^(j^k-1))).

%e Square array begins:

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

%e 3, 5, 17, 257, ...

%e 4, 28, 19684, 7625597484988, ...

%e 7, 261, 4294967313, 340282366920938463463374607431768211713, ...

%t T[n_, k_] := DivisorSum[n, #^(#^k) &]; Table[T[k, n - k], {n, 1, 7}, {k, 1, n}] // Flatten (* _Amiram Eldar_, May 11 2021 *)

%Y Columns k=0..3 give A000203, A062796, A308671, A308672.

%Y Cf. A308676.

%K nonn,tabl

%O 1,3

%A _Seiichi Manyama_, Jun 16 2019

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Last modified December 9 01:52 EST 2021. Contains 349625 sequences. (Running on oeis4.)