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 1-10 of 13 results. Next

A243978 Triangle T(n,k), n>=0, 0<=k<=n, read by rows: T(n,k) is the number of partitions of n where the minimal multiplicity of any part is k.

Original entry on oeis.org

1, 0, 1, 0, 1, 1, 0, 2, 0, 1, 0, 3, 1, 0, 1, 0, 6, 0, 0, 0, 1, 0, 7, 2, 1, 0, 0, 1, 0, 13, 1, 0, 0, 0, 0, 1, 0, 16, 4, 0, 1, 0, 0, 0, 1, 0, 25, 2, 2, 0, 0, 0, 0, 0, 1, 0, 33, 6, 1, 0, 1, 0, 0, 0, 0, 1, 0, 49, 4, 2, 0, 0, 0, 0, 0, 0, 0, 1, 0, 61, 9, 3, 2, 0, 1, 0, 0, 0, 0, 0, 1, 0, 90, 6, 3, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 113, 16, 2, 2, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 156, 9, 7, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
Offset: 0

Views

Author

Joerg Arndt and Alois P. Heinz, Jun 28 2014

Keywords

Comments

T(0,0) = 1 by convention.
Row sums are A000041.

Examples

			Triangle starts:
00:  1;
01:  0,   1;
02:  0,   1,  1;
03:  0,   2,  0, 1;
04:  0,   3,  1, 0, 1;
05:  0,   6,  0, 0, 0, 1;
06:  0,   7,  2, 1, 0, 0, 1;
07:  0,  13,  1, 0, 0, 0, 0, 1;
08:  0,  16,  4, 0, 1, 0, 0, 0, 1;
09:  0,  25,  2, 2, 0, 0, 0, 0, 0, 1;
10:  0,  33,  6, 1, 0, 1, 0, 0, 0, 0, 1;
11:  0,  49,  4, 2, 0, 0, 0, 0, 0, 0, 0, 1;
12:  0,  61,  9, 3, 2, 0, 1, 0, 0, 0, 0, 0, 1;
13:  0,  90,  6, 3, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1;
14:  0, 113, 16, 2, 2, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1;
15:  0, 156,  9, 7, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;
16:  0, 198, 23, 3, 4, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1;
17:  0, 269, 18, 5, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;
18:  0, 334, 34, 9, 3, 1, 2, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1;
19:  0, 448, 27, 8, 3, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;
20:  0, 556, 51, 7, 6, 3, 2, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;
...
The A000041(9) = 30 partitions of 9 with the least multiplicities of any part are:
01:  [ 1 1 1 1 1 1 1 1 1 ]   9
02:  [ 1 1 1 1 1 1 1 2 ]   1
03:  [ 1 1 1 1 1 1 3 ]   1
04:  [ 1 1 1 1 1 2 2 ]   2
05:  [ 1 1 1 1 1 4 ]   1
06:  [ 1 1 1 1 2 3 ]   1
07:  [ 1 1 1 1 5 ]   1
08:  [ 1 1 1 2 2 2 ]   3
09:  [ 1 1 1 2 4 ]   1
10:  [ 1 1 1 3 3 ]   2
11:  [ 1 1 1 6 ]   1
12:  [ 1 1 2 2 3 ]   1
13:  [ 1 1 2 5 ]   1
14:  [ 1 1 3 4 ]   1
15:  [ 1 1 7 ]   1
16:  [ 1 2 2 2 2 ]   1
17:  [ 1 2 2 4 ]   1
18:  [ 1 2 3 3 ]   1
19:  [ 1 2 6 ]   1
20:  [ 1 3 5 ]   1
21:  [ 1 4 4 ]   1
22:  [ 1 8 ]   1
23:  [ 2 2 2 3 ]   1
24:  [ 2 2 5 ]   1
25:  [ 2 3 4 ]   1
26:  [ 2 7 ]   1
27:  [ 3 3 3 ]   3
28:  [ 3 6 ]   1
29:  [ 4 5 ]   1
30:  [ 9 ]   1
Therefore row n=9 is [0, 25, 2, 2, 0, 0, 0, 0, 0, 1].
		

Crossrefs

Cf. A183568, A242451 (the same for compositions).
Cf. A091602 (partitions by max multiplicity of any part).

Programs

  • Maple
    b:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0,
          b(n, i-1, k) +add(b(n-i*j, i-1, k), j=max(1, k)..n/i)))
        end:
    T:= (n, k)-> b(n$2, k) -`if`(n=0 and k=0, 0, b(n$2, k+1)):
    seq(seq(T(n, k), k=0..n), n=0..14);
  • Mathematica
    b[n_, i_, k_] := b[n, i, k] = If[n == 0, 1, If[i<1, 0, b[n, i-1, k] + Sum[b[n-i*j, i-1, k], {j, Max[1, k], n/i}]]]; T[n_, k_] := b[n, n, k] - If[n == 0 && k == 0, 0, b[n, n, k+1]]; Table[Table[T[n, k], {k, 0, n}], {n, 0, 14}] // Flatten (* Jean-François Alcover, Jan 08 2015, translated from Maple *)

A242447 Number T(n,k) of compositions of n in which the maximal multiplicity of parts equals k; triangle T(n,k), n>=0, 0<=k<=n, read by rows.

Original entry on oeis.org

1, 0, 1, 0, 1, 1, 0, 3, 0, 1, 0, 3, 4, 0, 1, 0, 5, 6, 4, 0, 1, 0, 11, 10, 5, 5, 0, 1, 0, 13, 21, 18, 5, 6, 0, 1, 0, 19, 40, 34, 21, 6, 7, 0, 1, 0, 27, 87, 59, 40, 27, 7, 8, 0, 1, 0, 57, 121, 132, 100, 49, 35, 8, 9, 0, 1, 0, 65, 219, 272, 210, 131, 63, 44, 9, 10, 0, 1
Offset: 0

Views

Author

Alois P. Heinz, May 15 2014

Keywords

Comments

T(0,0) = 1 by convention. T(n,k) counts the compositions of n in which at least one part has multiplicity k and no part has a multiplicity larger than k.

Examples

			T(6,1) = 11: [1,2,3], [1,3,2], [2,1,3], [2,3,1], [3,1,2], [3,2,1], [2,4], [4,2], [1,5], [5,1], [6].
T(6,2) = 10: [1,1,2,2], [1,2,1,2], [1,2,2,1], [2,1,1,2], [2,1,2,1], [2,2,1,1], [3,3], [1,1,4], [1,4,1], [4,1,1].
T(6,3) = 5: [2,2,2], [1,1,1,3], [1,1,3,1], [1,3,1,1], [3,1,1,1].
T(6,4) = 5: [1,1,1,1,2], [1,1,1,2,1], [1,1,2,1,1], [1,2,1,1,1], [2,1,1,1,1].
T(6,6) = 1: [1,1,1,1,1,1].
Triangle T(n,k) begins:
  1;
  0,  1;
  0,  1,   1;
  0,  3,   0,   1;
  0,  3,   4,   0,   1;
  0,  5,   6,   4,   0,  1;
  0, 11,  10,   5,   5,  0,  1;
  0, 13,  21,  18,   5,  6,  0, 1;
  0, 19,  40,  34,  21,  6,  7, 0, 1;
  0, 27,  87,  59,  40, 27,  7, 8, 0, 1;
  0, 57, 121, 132, 100, 49, 35, 8, 9, 0, 1;
		

Crossrefs

Columns k=0-10 give: A000007, A032020 (for n>0), A243119, A243120, A243121, A243122, A243123, A243124, A243125, A243126, A243127.
T(2n,n) = A232665(n).
Row sums give A011782.
Cf. A242451 (the same for minimal multiplicity).

Programs

  • Maple
    b:= proc(n, i, p, k) option remember; `if`(n=0, p!, `if`(i<1, 0,
          add(b(n-i*j, i-1, p+j, k)/j!, j=0..min(n/i, k))))
        end:
    T:= (n, k)-> b(n$2, 0, k) -`if`(k=0, 0, b(n$2, 0, k-1)):
    seq(seq(T(n, k), k=0..n), n=0..14);
  • Mathematica
    b[n_, i_, p_, k_] := b[n, i, p, k] = If[n == 0, p!, If[i<1, 0, Sum[b[n - i*j, i-1, p + j, k]/j!, {j, 0, Min[n/i, k]}]]]; T[n_, k_] := b[n, n, 0, k] - If[k == 0, 0, b[n, n, 0, k-1]]; Table[Table[T[n, k], {k, 0, n}], {n, 0, 14}] // Flatten (* Jean-François Alcover, Jan 22 2015, after Alois P. Heinz *)

A244164 Number of compositions of n in which the minimal multiplicity of parts equals 1.

Original entry on oeis.org

1, 1, 3, 6, 15, 23, 53, 94, 203, 404, 855, 1648, 3416, 6662, 13400, 26406, 53038, 105306, 212051, 422162, 849267, 1696864, 3406077, 6807024, 13642099, 27268122, 54576003, 109096436, 218250874, 436243705, 872533347, 1744312748, 3488432736, 6974783481
Offset: 1

Views

Author

Alois P. Heinz, Jun 21 2014

Keywords

Examples

			From _Gus Wiseman_, Nov 25 2019: (Start)
The a(1) = 1 through a(5) = 15 compositions:
  (1)  (2)  (3)    (4)      (5)
            (1,2)  (1,3)    (1,4)
            (2,1)  (3,1)    (2,3)
                   (1,1,2)  (3,2)
                   (1,2,1)  (4,1)
                   (2,1,1)  (1,1,3)
                            (1,2,2)
                            (1,3,1)
                            (2,1,2)
                            (2,2,1)
                            (3,1,1)
                            (1,1,1,2)
                            (1,1,2,1)
                            (1,2,1,1)
                            (2,1,1,1)
(End)
		

Crossrefs

Column k=1 of A242451.
The complement is counted by A240085.

Programs

  • Maple
    b:= proc(n, i, p, k) option remember; `if`(n=0, p!, `if`(i<1, 0,
          add(b(n-i*j, i-1, p+j, k)/j!, j=[0, $max(1, k)..n/i])))
        end:
    a:= n-> b(n$2, 0, 1) -b(n$2, 0, 2):
    seq(a(n), n=1..50);
  • Mathematica
    Table[Length[Select[Join@@Permutations/@IntegerPartitions[n],Min@@Length/@Split[Sort[#]]==1&]],{n,0,10}] (* Gus Wiseman, Nov 25 2019 *)

Formula

a(n) = 2^(n-1) - A240085(n). - Gus Wiseman, Nov 25 2019

A244174 Number of compositions of 3n in which the minimal multiplicity of parts equals n.

Original entry on oeis.org

1, 3, 7, 21, 71, 253, 925, 3433, 12871, 48621, 184757, 705433, 2704157, 10400601, 40116601, 155117521, 601080391, 2333606221, 9075135301, 35345263801, 137846528821, 538257874441, 2104098963721, 8233430727601, 32247603683101, 126410606437753, 495918532948105
Offset: 0

Views

Author

Alois P. Heinz, Jun 21 2014

Keywords

Examples

			a(2) = 7: [1,1,2,2], [1,2,1,2], [1,2,2,1], [2,1,1,2], [2,1,2,1], [2,2,1,1], [3,3].
		

Crossrefs

Programs

  • Maple
    a:= proc(n) option remember;
          `if`(n<3, 2^(n+1)-1, ((15*n^2-31*n+12) *a(n-1)
           -2*(3*n-2)*(2*n-3) *a(n-2)) / ((3*n-5)*n))
        end:
    seq(a(n), n=0..30);
  • Mathematica
    a[n_] := a[n] = If[n < 3, 2^(n+1) - 1, ((15*n^2 - 31*n + 12)*a[n-1] - 2*(3*n - 2)*(2*n - 3)*a[n-2])/((3*n - 5)*n)]; Table[a[n], {n, 0, 30}] (* Jean-François Alcover, Nov 07 2014, after Alois P. Heinz *)
  • Sage
    A244174 = lambda m: SetPartitions(2*m,[2*m]).cardinality()+2*SetPartitions(2*m,[m,m]).cardinality()
    [1] + [A244174(m) for m in (1..26)] # Peter Luschny, Aug 02 2015

Formula

a(n) = A242451(3n,n).
Recurrence: see Maple program.
For n>0, a(n) = 1 + C(2n,n) = 1 + A000984(n). - Vaclav Kotesovec, Jun 21 2014
G.f.: 1/(sqrt(1-4*x)) + x/(1-x). - Alois P. Heinz, Jun 22 2014
a(n) = A245732(2n,n). - Alois P. Heinz, Jul 30 2014
a(n) = A065567(2n,n) for n>=1. - Alois P. Heinz, Sep 05 2023

A244169 Number of compositions of n in which the minimal multiplicity of parts equals 6.

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 925, 1716, 4719, 5005, 11011, 12376, 24494, 28848, 49771, 60985, 94997, 113323, 176576, 205948, 300841, 362000, 502840, 588343, 17972200, 47500741, 164220317, 452654380, 1198032651, 2936508011, 6683727408, 15107475055
Offset: 6

Views

Author

Alois P. Heinz, Jun 21 2014

Keywords

Crossrefs

Column k=6 of A242451.

Programs

  • Maple
    b:= proc(n, i, p, k) option remember; `if`(n=0, p!, `if`(i<1, 0,
          add(b(n-i*j, i-1, p+j, k)/j!, j=[0, $max(1, k)..n/i])))
        end:
    a:= n-> b(n$2, 0, 6) -b(n$2, 0, 7):
    seq(a(n), n=6..50);

A244165 Number of compositions of n in which the minimal multiplicity of parts equals 2.

Original entry on oeis.org

1, 0, 1, 0, 7, 10, 32, 31, 71, 77, 222, 342, 971, 1936, 4681, 9662, 19440, 38304, 76458, 143542, 281447, 536472, 1051100, 2039870, 4055916, 8030958, 16168611, 32510383, 65705473, 132895297, 269206168, 544002516, 1099360989, 2217243856, 4464684513, 8975720721
Offset: 2

Views

Author

Alois P. Heinz, Jun 21 2014

Keywords

Crossrefs

Column k=2 of A242451.

Programs

  • Maple
    b:= proc(n, i, p, k) option remember; `if`(n=0, p!, `if`(i<1, 0,
          add(b(n-i*j, i-1, p+j, k)/j!, j=[0, $max(1, k)..n/i])))
        end:
    a:= n-> b(n$2, 0, 2) -b(n$2, 0, 3):
    seq(a(n), n=2..50);

A244166 Number of compositions of n in which the minimal multiplicity of parts equals 3.

Original entry on oeis.org

1, 0, 0, 1, 0, 0, 21, 35, 91, 105, 211, 221, 464, 441, 740, 2571, 5457, 14740, 37990, 89091, 203487, 416751, 877183, 1722277, 3374384, 6381902, 12054327, 22545335, 42054605, 78409434, 147669414, 280480248, 539039384, 1051964654, 2078682442, 4165775779
Offset: 3

Views

Author

Alois P. Heinz, Jun 21 2014

Keywords

Crossrefs

Column k=3 of A242451.

Programs

  • Maple
    b:= proc(n, i, p, k) option remember; `if`(n=0, p!, `if`(i<1, 0,
          add(b(n-i*j, i-1, p+j, k)/j!, j=[0, $max(1, k)..n/i])))
        end:
    a:= n-> b(n$2, 0, 3) -b(n$2, 0, 4):
    seq(a(n), n=3..50);

A244167 Number of compositions of n in which the minimal multiplicity of parts equals 4.

Original entry on oeis.org

1, 0, 0, 0, 1, 0, 0, 0, 71, 126, 336, 330, 776, 841, 1541, 1821, 2951, 3221, 5322, 5697, 43288, 99626, 313917, 807218, 2049995, 4769054, 10240287, 22002219, 45015647, 90239153, 177239582, 342276724, 650127448, 1223160912, 2275920969, 4197371497, 7754873919
Offset: 4

Views

Author

Alois P. Heinz, Jun 21 2014

Keywords

Crossrefs

Column k=4 of A242451.

Programs

  • Maple
    b:= proc(n, i, p, k) option remember; `if`(n=0, p!, `if`(i<1, 0,
          add(b(n-i*j, i-1, p+j, k)/j!, j=[0, $max(1, k)..n/i])))
        end:
    a:= n-> b(n$2, 0, 4) -b(n$2, 0, 5):
    seq(a(n), n=4..50);

A244168 Number of compositions of n in which the minimal multiplicity of parts equals 5.

Original entry on oeis.org

1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 253, 462, 1254, 1287, 2794, 3256, 6117, 6980, 12319, 13630, 22015, 25971, 38144, 43966, 64863, 828898, 2119622, 7035420, 18918950, 48777982, 117594112, 259516217, 574862404, 1204750520, 2487540831, 5003559312, 9935325156
Offset: 5

Views

Author

Alois P. Heinz, Jun 21 2014

Keywords

Crossrefs

Column k=5 of A242451.

Programs

  • Maple
    b:= proc(n, i, p, k) option remember; `if`(n=0, p!, `if`(i<1, 0,
          add(b(n-i*j, i-1, p+j, k)/j!, j=[0, $max(1, k)..n/i])))
        end:
    a:= n-> b(n$2, 0, 5) -b(n$2, 0, 6):
    seq(a(n), n=5..50);

A244170 Number of compositions of n in which the minimal multiplicity of parts equals 7.

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 3433, 6435, 17875, 19448, 43264, 50388, 96968, 119713, 208803, 256597, 422375, 512524, 785708, 976990, 1423465, 1737759, 2488824, 3001562, 4141412, 5012060, 6722158, 407104665, 1108110431, 3914660472, 10999975393
Offset: 7

Views

Author

Alois P. Heinz, Jun 21 2014

Keywords

Crossrefs

Column k=7 of A242451.

Programs

  • Maple
    b:= proc(n, i, p, k) option remember; `if`(n=0, p!, `if`(i<1, 0,
          add(b(n-i*j, i-1, p+j, k)/j!, j=[0, $max(1, k)..n/i])))
        end:
    a:= n-> b(n$2, 0, 7) -b(n$2, 0, 8):
    seq(a(n), n=7..55);
Showing 1-10 of 13 results. Next