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A292193
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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).
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8
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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, 33, 98, 164, 107, 56, 15, 1, 1, 65, 276, 610, 505, 352, 97, 22, 1, 1, 129, 794, 2324, 2531, 2474, 789, 198, 30, 1, 1, 257, 2316, 8986, 13225, 18580, 7273, 2314, 354, 42
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OFFSET
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0,6
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LINKS
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FORMULA
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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
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EXAMPLE
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Square array begins:
1, 1, 1, 1, 1, ...
1, 1, 1, 1, 1, ...
2, 3, 5, 9, 17, ...
3, 6, 14, 36, 98, ...
5, 14, 46, 164, 610, ...
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MAPLE
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b:= proc(n, i, k) option remember; `if`(n=0 or i=1, 1,
`if`(i>n, 0, i^k*b(n-i, i, k))+b(n, i-1, k))
end:
A:= (n, k)-> b(n$2, k):
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MATHEMATICA
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m = 12;
col[k_] := col[k] = Product[1/(1 - j^k*x^j), {j, 1, m}] + O[x]^(m+1) // CoefficientList[#, x]&;
A[n_, k_] := col[k][[n+1]];
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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