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 1-8 of 8 results.

A098859 Number of partitions of n into parts each of which is used a different number of times.

Original entry on oeis.org

1, 1, 2, 2, 4, 5, 7, 10, 13, 15, 21, 28, 31, 45, 55, 62, 82, 105, 116, 153, 172, 208, 251, 312, 341, 431, 492, 588, 676, 826, 905, 1120, 1249, 1475, 1676, 2003, 2187, 2625, 2922, 3409, 3810, 4481, 4910, 5792, 6382, 7407, 8186, 9527, 10434
Offset: 0

Views

Author

David S. Newman, Oct 11 2004

Keywords

Comments

Fill, Janson and Ward refer to these partitions as Wilf partitions. - Peter Luschny, Jun 04 2012

Examples

			a(6)=7 because 6= 4+1+1= 3+3= 3+1+1+1= 2+2+2= 2+1+1+1+1= 1+1+1+1+1+1. Four unrestricted partitions of 6 are not counted by a(6): 5+1, 4+2, 3+2+1 because at least two different summands are each used once; 2+2+1+1 because each summand is used twice.
From _Gus Wiseman_, Apr 19 2019: (Start)
The a(1) = 1 through a(9) = 15 partitions are the following. The Heinz numbers of these partitions are given by A130091.
  1   2    3     4      5       6        7         8          9
      11   111   22     221     33       322       44         333
                 211    311     222      331       332        441
                 1111   2111    411      511       422        522
                        11111   3111     2221      611        711
                                21111    4111      2222       3222
                                111111   22111     5111       6111
                                         31111     22211      22221
                                         211111    41111      33111
                                         1111111   221111     51111
                                                   311111     411111
                                                   2111111    2211111
                                                   11111111   3111111
                                                              21111111
                                                              111111111
(End)
		

Crossrefs

Row sums of A182485.
Cf. A047966 (each part appears the same number of times), A090858, A116608, A130091, A325242.

Programs

Formula

log(a(n)) ~ N*log(N) where N = (6*n)^(1/3) (see Fill, Janson and Ward). - Peter Luschny, Jun 04 2012

Extensions

Corrected and extended by Vladeta Jovovic, Oct 22 2004

A242896 Number T(n,k) of compositions of n into k parts with distinct multiplicities, where parts are counted without multiplicities; triangle T(n,k), n>=0, 0<=k<=max{i:A000292(i)<=n}, read by rows.

Original entry on oeis.org

1, 0, 1, 0, 2, 0, 2, 0, 3, 3, 0, 2, 10, 0, 4, 12, 0, 2, 38, 0, 4, 56, 0, 3, 79, 0, 4, 152, 60, 0, 2, 251, 285, 0, 6, 284, 498, 0, 2, 594, 1438, 0, 4, 920, 2816, 0, 4, 1108, 5208, 0, 5, 2136, 11195, 0, 2, 3402, 24094, 0, 6, 4407, 38523, 0, 2, 8350, 85182
Offset: 0

Views

Author

Alois P. Heinz, May 25 2014

Keywords

Examples

			T(5,1) = 2: [1,1,1,1,1], [5].
T(5,2) = 10: [1,1,1,2], [1,1,2,1], [1,2,1,1], [2,1,1,1], [1,2,2], [2,1,2], [2,2,1], [1,1,3], [1,3,1], [3,1,1].
Triangle T(n,k) begins:
  1;
  0, 1;
  0, 2;
  0, 2;
  0, 3,   3;
  0, 2,  10;
  0, 4,  12;
  0, 2,  38;
  0, 4,  56;
  0, 3,  79;
  0, 4, 152, 60;
		

Crossrefs

Row sums give A242882.
Cf. A182485 (the same for partitions), A242887.

Programs

  • Maple
    b:= proc(n, i, s) option remember; `if`(n=0, add(j, j=s)!,
          `if`(i<1, 0, expand(add(`if`(j>0 and j in s, 0, `if`(j=0, 1, x)*
           b(n-i*j, i-1, `if`(j=0, s, s union {j}))/j!), j=0..n/i))))
        end:
    T:= n-> (p-> seq(coeff(p, x, i), i=0..degree(p)))(b(n$2, {})):
    seq(T(n), n=0..16);
  • Mathematica
    b[n_, i_, s_List] := b[n, i, s] = If[n == 0, Total[s]!, If[i<1, 0, Expand[ Sum[ If[j>0 && MemberQ[s, j], 0, If[j == 0, 1, x]*b[n-i*j, i-1, If[j == 0, s, s ~Union~ {j}]]/j!], {j, 0, n/i}]]]]; T[n_] := Function[{p}, Table[Coefficient[p, x, i], {i, 0, Exponent[p, x]}]][b[n, n, {}]]; Table[T[n], {n, 0, 16}] // Flatten (* Jean-François Alcover, Feb 11 2015, after Alois P. Heinz *)

A182473 Number of partitions of n into exactly 2 different parts with distinct multiplicities.

Original entry on oeis.org

0, 0, 0, 0, 1, 3, 3, 8, 9, 12, 16, 22, 20, 31, 35, 34, 44, 51, 53, 62, 65, 68, 87, 86, 89, 95, 118, 108, 126, 127, 138, 142, 162, 154, 188, 160, 193, 189, 227, 204, 228, 221, 258, 238, 282, 247, 311, 272, 320, 284, 344, 318, 373, 327, 398, 334, 407, 380, 450
Offset: 0

Views

Author

Alois P. Heinz, Apr 30 2012

Keywords

Examples

			a(4) = 1: [2,1,1], part 2 occurs once and part 1 occurs twice.
a(5) = 3: [2,1,1,1], [2,2,1], [3,1,1].
a(6) = 3: [2,1,1,1,1], [3,1,1,1], [4,1,1].
a(7) = 8: [2,1,1,1,1,1], [2,2,1,1,1], [2,2,2,1], [3,1,1,1,1], [3,2,2], [3,3,1], [4,1,1,1], [5,1,1].
		

Crossrefs

Column k=2 of A182485.
Cf. A242900 (the same for compositions).

A212114 Number of partitions of n into exactly 3 different parts with distinct multiplicities.

Original entry on oeis.org

1, 4, 5, 12, 16, 24, 33, 52, 57, 89, 100, 131, 152, 207, 215, 292, 311, 381, 424, 527, 535, 679, 714, 826, 901, 1074, 1075, 1304, 1361, 1522, 1643, 1881, 1900, 2221, 2297, 2517, 2700, 3016, 3032, 3478, 3602, 3846, 4098, 4513, 4574, 5092, 5278, 5568, 5957, 6412
Offset: 10

Views

Author

Alois P. Heinz, May 01 2012

Keywords

Examples

			a(10) = 1: [3,2,2,1,1,1].
a(11) = 4: [3,2,2,1,1,1,1], [3,2,2,2,1,1], [3,3,2,1,1,1], [4,2,2,1,1,1].
a(12) = 5: [3,2,2,1,1,1,1,1], [3,3,2,1,1,1,1], [4,2,2,1,1,1,1], [4,2,2,2,1,1], [5,2,2,1,1,1].
		

Crossrefs

Column k=3 of A182485.

A212115 Number of partitions of n into exactly 4 different parts with distinct multiplicities.

Original entry on oeis.org

1, 5, 8, 17, 29, 41, 59, 95, 120, 170, 224, 297, 367, 491, 583, 764, 904, 1118, 1306, 1631, 1863, 2269, 2576, 3099, 3479, 4179, 4583, 5456, 6029, 7041, 7693, 8978, 9745, 11274, 12174, 14037, 15074, 17202, 18383, 20978, 22404, 25276, 26825, 30271, 32092, 36051
Offset: 20

Views

Author

Alois P. Heinz, May 01 2012

Keywords

Examples

			a(20) = 1: [4,3,3,2,2,2,1,1,1,1].
a(21) = 5: [4,3,3,2,2,2,1,1,1,1,1], [4,3,3,2,2,2,2,1,1,1], [4,3,3,3,2,2,1,1,1,1], [4,4,3,2,2,2,1,1,1,1], [5,3,3,2,2,2,1,1,1,1].
a(22) = 8: [4,3,3,2,2,2,1,1,1,1,1,1], [4,3,3,3,2,2,1,1,1,1,1], [4,4,3,2,2,2,1,1,1,1,1], [4,4,3,2,2,2,2,1,1,1], [5,3,3,2,2,2,1,1,1,1,1], [5,3,3,2,2,2,2,1,1,1], [5,3,3,3,2,2,1,1,1,1], [6,3,3,2,2,2,1,1,1,1].
		

Crossrefs

Column k=4 of A182485.

A212116 Number of partitions of n into exactly 5 different parts with distinct multiplicities.

Original entry on oeis.org

1, 6, 12, 24, 48, 68, 108, 168, 232, 318, 458, 588, 781, 1043, 1298, 1663, 2147, 2603, 3216, 4039, 4814, 5822, 7103, 8356, 9936, 11902, 13784, 16160, 19082, 21841, 25301, 29399, 33450, 38226, 44084, 49543, 56381, 64047, 71870, 80596, 91459, 101249, 113545
Offset: 35

Views

Author

Alois P. Heinz, May 01 2012

Keywords

Examples

			a(35) = 1: [5,4,4,3,3,3,2,2,2,2,1,1,1,1,1].
a(36) = 6: [5,4,4,3,3,3,2,2,2,2,1,1,1,1,1,1], [5,4,4,3,3,3,2,2,2,2,2,1,1,1,1], [5,4,4,3,3,3,3,2,2,2,1,1,1,1,1], [5,4,4,4,3,3,2,2,2,2,1,1,1,1,1], [5,5,4,3,3,3,2,2,2,2,1,1,1,1,1], [6,4,4,3,3,3,2,2,2,2,1,1,1,1,1].
		

Crossrefs

Column k=5 of A182485.

A212117 Number of partitions of n into exactly 6 different parts with distinct multiplicities.

Original entry on oeis.org

1, 7, 17, 34, 74, 113, 186, 289, 434, 598, 888, 1162, 1610, 2115, 2783, 3534, 4716, 5756, 7364, 9125, 11404, 13721, 17206, 20391, 24983, 29767, 35781, 41987, 50733, 58665, 69642, 80987, 95040, 109085, 128243, 145889, 169528, 193419, 222437, 251663, 290151
Offset: 56

Views

Author

Alois P. Heinz, May 01 2012

Keywords

Examples

			a(56) = 1: [6,5,5,4,4,4,3,3,3,3,2,2,2,2,2,1,1,1,1,1,1].
a(57) = 7: [6,5,5,4,4,4,3,3,3,3,2,2,2,2,2,1,1,1,1,1,1,1],[6,5,5,4,4,4,3,3,3,3,2,2,2,2,2,2,1,1,1,1,1],[6,5,5,4,4,4,3,3,3,3,3,2,2,2,2,1,1,1,1,1,1],
  [6,5,5,4,4,4,4,3,3,3,2,2,2,2,2,1,1,1,1,1,1], [6,5,5,5,4,4,3,3,3,3,2,2,2,2,2,1,1,1,1,1,1],
  [6,6,5,4,4,4,3,3,3,3,2,2,2,2,2,1,1,1,1,1,1],[7,5,5,4,4,4,3,3,3,3,2,2,2,2,2,1,1,1,1,1,1].
		

Crossrefs

Column k=6 of A182485.

A212118 Number of partitions of n into exactly 7 different parts with distinct multiplicities.

Original entry on oeis.org

1, 8, 23, 48, 109, 184, 306, 496, 774, 1096, 1655, 2272, 3175, 4264, 5794, 7424, 9992, 12585, 16255, 20354, 25979, 31619, 39971, 48283, 59782, 71799, 87907, 104004, 126743, 148911, 178680, 209259, 249489, 288937, 342755, 395090, 464036
Offset: 84

Views

Author

Alois P. Heinz, May 01 2012

Keywords

Examples

			a(84) = 1: [7,6,6,5,5,5,4,4,4,4,3,3,3,3,3,2,2,2,2,2,2,1,1,1,1,1,1,1].
		

Crossrefs

Column k=7 of A182485.
Showing 1-8 of 8 results.