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A293525 Square array A(n,k), n >= 0, k >= 1, read by antidiagonals, where column k is the expansion of e.g.f. Product_{j > 0, j mod k > 0} exp(x^j). 2

%I #26 Oct 15 2017 01:05:52

%S 1,1,0,1,1,0,1,1,1,0,1,1,3,7,0,1,1,3,7,25,0,1,1,3,13,49,181,0,1,1,3,

%T 13,49,321,1201,0,1,1,3,13,73,381,2131,10291,0,1,1,3,13,73,381,2971,

%U 19783,97777,0,1,1,3,13,73,501,3331,26713,195777,1013545,0,1,1

%N Square array A(n,k), n >= 0, k >= 1, read by antidiagonals, where column k is the expansion of e.g.f. Product_{j > 0, j mod k > 0} exp(x^j).

%H Seiichi Manyama, <a href="/A293525/b293525.txt">Antidiagonals n = 0..139, flattened</a>

%F E.g.f. of column k: exp((Sum_{j=1..k-1} x^j)/(1 - x^k)).

%e Square array begins:

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

%e 0, 1, 1, 1, 1, ...

%e 0, 1, 3, 3, 3, ...

%e 0, 7, 7, 13, 13, ...

%e 0, 25, 49, 49, 73, ...

%e 0, 181, 321, 381, 381, ...

%t kmax = 12; col[k_] := PadRight[(Exp[Sum[x^j, {j, 1, k - 1}]/(1 - x^k)] + O[x]^kmax // CoefficientList[#, x] &), kmax]*Range[0, kmax - 1]!; A = Array[col, kmax]; Table[A[[n - k + 1, k]], {n, 1, kmax}, {k, 1, n}] // Flatten (* _Jean-François Alcover_, Oct 12 2017, from formula *)

%Y Columns k=1..3 give A000007, A088009, A113775.

%Y Rows n=0 gives A000012.

%Y Main diagonal gives A000262.

%Y Cf. A293530.

%K nonn,tabl

%O 0,13

%A _Seiichi Manyama_, Oct 11 2017

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Last modified April 25 08:27 EDT 2024. Contains 371964 sequences. (Running on oeis4.)