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Total sum T(n,k) of number of lambda-parking functions of partitions lambda of n into distinct parts with largest part k; triangle T(n,k), k>=0, k<=n<=k*(k+1)/2, read by columns.
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%I #22 Feb 11 2017 09:51:14

%S 1,1,2,3,3,5,8,16,4,7,12,40,34,50,125,5,9,16,55,73,132,281,351,307,

%T 432,1296,6,11,20,70,96,212,469,642,1020,1361,3294,3305,3910,3506,

%U 4802,16807,7,13,24,85,119,267,644,959,1567,2686,5570,7109,11890,13234

%N Total sum T(n,k) of number of lambda-parking functions of partitions lambda of n into distinct parts with largest part k; triangle T(n,k), k>=0, k<=n<=k*(k+1)/2, read by columns.

%H Alois P. Heinz, <a href="/A265019/b265019.txt">Columns k = 0..22, flattened</a>

%H R. Stanley, <a href="http://math.mit.edu/~rstan/transparencies/parking.pdf">Parking Functions</a>, 2011.

%F T(A000217(n),n) = A000272(n+1).

%e Triangle T(n,k) begins:

%e 00 : 1;

%e 01 : 1;

%e 02 : 2;

%e 03 : 3, 3;

%e 04 : 5, 4;

%e 05 : 8, 7, 5;

%e 06 : 16, 12, 9, 6;

%e 07 : 40, 16, 11, 7;

%e 08 : 34, 55, 20, 13, 8;

%e 09 : 50, 73, 70, 24, 15, 9;

%e 10 : 125, 132, 96, 85, 28, 17, 10;

%e 11 : 281, 212, 119, 100, 32, 19, 11;

%e 12 : 351, 469, 267, 142, 115, 36, 21, 12;

%p p:= l-> (n-> n!*LinearAlgebra[Determinant](Matrix(n, (i, j)

%p -> (t->`if`(t<0, 0, l[i]^t/t!))(j-i+1))))(nops(l)):

%p g:= (n, i, l)-> `if`(i*(i+1)/2<n, 0, `if`(n=0, p(l)*x^

%p `if`(l=[], 0, l[-1]), g(n, i-1, l)+

%p `if`(i>n, 0, g(n-i, i-1, [i, l[]])))):

%p b:= proc(n) option remember; g(n$2, []) end:

%p T:= k-> seq(coeff(b(n), x, k), n=k..k*(k+1)/2):

%p seq(T(k), k=0..8);

%t p[l_] := With[{n = Length[l]}, n!*Det[Table[t = j-i+1; If[t<0, 0, l[[i]]^t/t!], {i, 1, n}, {j, 1, n}]]]; g[n_, i_, l_] := g[n, i, l] = If[i*(i+1)/2<n, 0, If[n==0, p[l]*x^If[l=={}, 0, l[[-1]]], g[n, i-1, l] + If[i>n, 0, g[n-i, i-1, Join[{i}, l]]]]]; b[n_] := b[n] = g[n, n, {}]; T[0] = {1}; T[k_] := Table[Coefficient[b[n], x, k], {n, k, k*(k+1)/2}]; Table[T[k], {k, 0, 8}] // Flatten (* _Jean-François Alcover_, Feb 11 2017, translated from Maple *)

%Y Row sums give A265016.

%Y Column sums give A265130.

%Y Cf. A000217, A000272, A265018 (the same read by rows).

%K nonn,tabf

%O 0,3

%A _Alois P. Heinz_, Nov 30 2015