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Number T(n,k) of partitions of n, where k is the difference between the number of odd parts and the number of even parts, both counted without multiplicity; triangle T(n,k), n>=0, read by rows.
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%I #29 Dec 12 2016 02:28:24

%S 1,1,1,0,1,1,2,2,1,1,1,4,2,1,1,2,3,3,2,1,8,3,3,2,4,6,5,5,4,13,8,4,1,5,

%T 5,11,13,7,1,11,20,14,9,2,1,6,13,17,26,11,3,1,22,31,27,15,5,2,12,18,

%U 34,44,18,7,4,40,47,51,23,11,5,16,36,56,72,34,11,1

%N Number T(n,k) of partitions of n, where k is the difference between the number of odd parts and the number of even parts, both counted without multiplicity; triangle T(n,k), n>=0, read by rows.

%C T(n,0) = A241638(n).

%C Sum_{k<0} T(n,k) = A241640(n).

%C Sum_{k<=0} T(n,k) = A241639(n).

%C Sum_{k>=0} T(n,k) = A241637(n).

%C Sum_{k>0} T(n,k) = A241636(n).

%C T(n^2,n) = T(n^2+n,-n) = 1.

%C T(n^2+n,n) = Sum_{k} T(n,k) = A000041(n).

%C T(n^2+3*n,-n) = A000712(n).

%H Alois P. Heinz, <a href="/A242618/b242618.txt">Rows n = 0..500, flattened</a>

%e Triangle T(n,k) begins:

%e : n\k : -3 -2 -1 0 1 2 3 ...

%e +-----+---------------------------

%e : 0 : 1;

%e : 1 : 1;

%e : 2 : 1, 0, 1;

%e : 3 : 1, 2;

%e : 4 : 2, 1, 1, 1;

%e : 5 : 4, 2, 1;

%e : 6 : 1, 2, 3, 3, 2;

%e : 7 : 1, 8, 3, 3;

%e : 8 : 2, 4, 6, 5, 5;

%e : 9 : 4, 13, 8, 4, 1;

%e : 10 : 5, 5, 11, 13, 7, 1;

%e : 11 : 11, 20, 14, 9, 2;

%e : 12 : 1, 6, 13, 17, 26, 11, 3;

%e : 13 : 1, 22, 31, 27, 15, 5;

%e : 14 : 2, 12, 18, 34, 44, 18, 7;

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

%p expand(b(n, i-1)+add(b(n-i*j, i-1)*x^(2*irem(i, 2)-1), j=1..n/i))))

%p end:

%p T:= n-> (p-> seq(coeff(p, x, i), i=ldegree(p)..degree(p)))(b(n$2)):

%p seq(T(n), n=0..20);

%t b[n_, i_] := b[n, i] = If[n == 0, 1, If[i < 1, 0, Expand[b[n, i - 1] + Sum[b[n - i*j, i - 1]*x^(2*Mod[i, 2] - 1), {j, 1, n/i}]]]]; T[n_] := Function[p, Table[Coefficient[p, x, i], {i, Exponent[p, x, Min], Exponent[p, x]}]][b[n, n]]; Table[T[n], {n, 0, 20}] // Flatten (* _Jean-François Alcover_, Dec 12 2016 after _Alois P. Heinz_ *)

%Y Columns k=(-10)-10 give: A242682, A242683, A242684, A242685, A242686, A242687, A242688, A242689, A242690, A242691, A241638, A242692, A242693, A242694, A242695, A242696, A242697, A242698, A242699, A242700, A242701.

%Y Row sums give A000041.

%Y Cf. A240009 (parts counted with multiplicity), A240021 (distinct parts), A242626 (compositions counted without multiplicity).

%K nonn,tabf,look

%O 0,7

%A _Alois P. Heinz_, May 19 2014