cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-3 of 3 results.

A265016 Total sum of number of lambda-parking functions, where lambda ranges over all partitions of n into distinct parts.

Original entry on oeis.org

1, 1, 2, 6, 9, 20, 43, 74, 130, 241, 493, 774, 1413, 2286, 3987, 7287, 11650, 19235, 31581, 50852, 80867, 141615, 214538, 349179, 541603, 859759, 1303221, 2054700, 3277493, 4960397, 7652897, 11662457, 17703655, 26603187, 40043433, 59384901, 92234897, 134538472
Offset: 0

Views

Author

Alois P. Heinz, Nov 30 2015

Keywords

Examples

			The number of lambda-parking functions induced by the partitions of 4 into distinct parts:
5 by [1,3]: [1,1], [1,2], [2,1], [1,3], [3,1],
4 by [4]: [1], [2], [3], [4].
a(4) = 5 + 4 = 9.
		

Crossrefs

Programs

  • Maple
    p:= l-> (n-> n!*LinearAlgebra[Determinant](Matrix(n, (i, j)
             -> (t->`if`(t<0, 0, l[i]^t/t!))(j-i+1))))(nops(l)):
    g:= (n, i, l)->  `if`(i*(i+1)/2n, 0, g(n-i, i-1, [i, l[]])))):
    a:= n-> g(n$2, []):
    seq(a(n), n=0..35);
  • Mathematica
    p[l_] := With[{n = Length[l]}, n!*Det[Table[Function[t,
         If[t < 0, 0, l[[i]]^t/t!]][j - i + 1], {i, n}, {j, n}]]];
    g[n_, i_, l_] := If[i (i + 1)/2 < n, 0, If[n == 0, p[l],
         g[n, i - 1, l] + If[i > n, 0, g[n - i, i - 1, Prepend[l, i]]]]];
    a[n_] := If[n == 0, 1, g[n, n, {}]];
    Table[a[n], {n, 0, 35}] (* Jean-François Alcover, Aug 20 2021, after Alois P. Heinz *)

A265018 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), n>=0, floor(sqrt(2n)+1/2)<=k<=n, read by rows.

Original entry on oeis.org

1, 1, 2, 3, 3, 5, 4, 8, 7, 5, 16, 12, 9, 6, 40, 16, 11, 7, 34, 55, 20, 13, 8, 50, 73, 70, 24, 15, 9, 125, 132, 96, 85, 28, 17, 10, 281, 212, 119, 100, 32, 19, 11, 351, 469, 267, 142, 115, 36, 21, 12, 307, 642, 644, 322, 165, 130, 40, 23, 13
Offset: 0

Views

Author

Alois P. Heinz, Nov 30 2015

Keywords

Examples

			Triangle T(n,k) begins:
00 :  1;
01 :     1;
02 :        2;
03 :        3,  3;
04 :            5,   4;
05 :            8,   7,   5;
06 :           16,  12,   9,   6;
07 :                40,  16,  11,   7;
08 :                34,  55,  20,  13,   8;
09 :                50,  73,  70,  24,  15,   9;
10 :               125, 132,  96,  85,  28,  17, 10;
11 :                    281, 212, 119, 100,  32, 19, 11;
12 :                    351, 469, 267, 142, 115, 36, 21, 12;
		

Crossrefs

Row sums give A265016.
Column sums give A265130.
Cf. A000217, A000272, A002024, A265019 (the same read by columns).

Programs

  • Maple
    p:= l-> (n-> n!*LinearAlgebra[Determinant](Matrix(n, (i, j)
             -> (t->`if`(t<0, 0, l[i]^t/t!))(j-i+1))))(nops(l)):
    g:= (n, i, l)-> `if`(i*(i+1)/2n, 0, g(n-i, i-1, [i, l[]])))):
    T:= n->(f->seq(coeff(f, x, i), i=ldegree(f)..degree(f)))(g(n$2, [])):
    seq(T(n), n=0..20);

Formula

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

A265130 Total sum of number of lambda-parking functions, where lambda ranges over all partitions of k into distinct parts with largest part n and n<=k<=n*(n+1)/2.

Original entry on oeis.org

1, 1, 5, 32, 272, 2957, 39531, 629806, 11673074, 247028567, 5881190801, 155651692748, 4534744862052, 144246963009697, 4975152075900887, 184958685188293274, 7373625038400716198, 313817002976857310507, 14201832585602869616349, 681022860320979979626232
Offset: 0

Views

Author

Alois P. Heinz, Dec 02 2015

Keywords

Crossrefs

Column sums of A265018, A265019.

Programs

  • Maple
    p:= l-> (n-> n!*LinearAlgebra[Determinant](Matrix(n, (i, j)
             -> (t->`if`(t<0, 0, l[i]^t/t!))(j-i+1))))(nops(l)):
    g:= (n, i, l)-> `if`(i*(i+1)/2n, 0, g(n-i, i-1, [i, l[]])))):
    a:= n-> `if`(n=0, 1, add(g(k-n, n-1, [n]), k=n..n*(n+1)/2)):
    seq(a(n), n=0..10);
  • Mathematica
    p[l_] := Function[n, n!*Det[Table[Function [t,
         If[t < 0, 0, l[[i]]^t/t!]][j - i + 1], {i, n}, {j, n}]]][Length[l]];
    g[n_, i_, l_] := If[i(i+1)/2 < n, 0,
         If[n == 0, p[l], g[n, i - 1, l] +
         If[i > n, 0, g[n - i, i - 1, Prepend[l, i]]]]];
    a[n_] := If[n == 0, 1, Sum[g[k - n, n - 1, {n}], {k, n, n(n+1)/2}]];
    Table[a[n], {n, 0, 15}] (* Jean-François Alcover, Aug 22 2021, after Alois P. Heinz *)
Showing 1-3 of 3 results.