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A308701 Square array A(n,k), n >= 1, k >= 0, read by antidiagonals, where A(n,k) is Sum_{d|n} d^(k*(d-1)). 4

%I #37 May 09 2021 02:50:40

%S 1,1,2,1,3,2,1,5,10,3,1,9,82,67,2,1,17,730,4101,626,4,1,33,6562,

%T 262153,390626,7788,2,1,65,59050,16777233,244140626,60466262,117650,4,

%U 1,129,531442,1073741857,152587890626,470184985314,13841287202,2097219,3

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

%H Seiichi Manyama, <a href="/A308701/b308701.txt">Antidiagonals n = 1..53, flattened</a>

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

%F G.f. of column k: Sum_{j>=1} j^(k*(j-1)) * x^j/(1 - x^j).

%e Square array begins:

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

%e 2, 3, 5, 9, 17, ...

%e 2, 10, 82, 730, 6562, ...

%e 3, 67, 4101, 262153, 16777233, ...

%e 2, 626, 390626, 244140626, 152587890626, ...

%t T[n_, k_] := DivisorSum[n, #^(k*(# - 1)) &]; Table[T[k, n - k], {n, 1, 9}, {k, 1, n}] // Flatten (* _Amiram Eldar_, May 09 2021 *)

%Y Columns k=0..2 give A000005, A262843, A308753.

%Y Row n=1..3 give A000012, A000051, A062396.

%Y Cf. A308694, A308698, A308704.

%K nonn,tabl

%O 1,3

%A _Seiichi Manyama_, Jun 22 2019

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Last modified April 25 04:42 EDT 2024. Contains 371964 sequences. (Running on oeis4.)