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A292193 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of Product_{j>=1} 1/(1 - j^k*x^j). 8

%I #29 Sep 07 2023 15:51:09

%S 1,1,1,1,1,2,1,1,3,3,1,1,5,6,5,1,1,9,14,14,7,1,1,17,36,46,25,11,1,1,

%T 33,98,164,107,56,15,1,1,65,276,610,505,352,97,22,1,1,129,794,2324,

%U 2531,2474,789,198,30,1,1,257,2316,8986,13225,18580,7273,2314,354,42

%N Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of Product_{j>=1} 1/(1 - j^k*x^j).

%H Seiichi Manyama, <a href="/A292193/b292193.txt">Antidiagonals n = 0..139, flattened</a>

%F A(0,k) = 1 and A(n,k) = (1/n) * Sum_{j=1..n} (Sum_{d|j} d^(1+k*j/d)) * A(n-j,k) for n > 0. - _Seiichi Manyama_, Nov 02 2017

%e Square array begins:

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

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

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

%e 3, 6, 14, 36, 98, ...

%e 5, 14, 46, 164, 610, ...

%p b:= proc(n, i, k) option remember; `if`(n=0 or i=1, 1,

%p `if`(i>n, 0, i^k*b(n-i, i, k))+b(n, i-1, k))

%p end:

%p A:= (n, k)-> b(n$2, k):

%p seq(seq(A(n, d-n), n=0..d), d=0..12); # _Alois P. Heinz_, Sep 11 2017

%t m = 12;

%t col[k_] := col[k] = Product[1/(1 - j^k*x^j), {j, 1, m}] + O[x]^(m+1) // CoefficientList[#, x]&;

%t A[n_, k_] := col[k][[n+1]];

%t Table[A[n, d-n], {d, 0, m}, {n, 0, d}] // Flatten (* _Jean-François Alcover_, Feb 11 2021 *)

%Y Columns k=0..5 give A000041, A006906, A077335, A265837, A265838, A265839.

%Y Rows 0+1, 2 give A000012, A000051.

%Y Main diagonal gives A292194.

%Y Cf. A292166.

%K nonn,tabl

%O 0,6

%A _Seiichi Manyama_, Sep 11 2017

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Last modified April 23 14:15 EDT 2024. Contains 371914 sequences. (Running on oeis4.)