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.

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A330463 Triangle read by rows where T(n,k) is the number of k-element sets of nonempty multisets of positive integers with total sum n.

Original entry on oeis.org

1, 0, 1, 0, 2, 0, 0, 3, 2, 0, 0, 5, 4, 0, 0, 0, 7, 11, 1, 0, 0, 0, 11, 20, 6, 0, 0, 0, 0, 15, 40, 16, 0, 0, 0, 0, 0, 22, 68, 40, 3, 0, 0, 0, 0, 0, 30, 120, 91, 11, 0, 0, 0, 0, 0, 0, 42, 195, 186, 41, 0, 0, 0, 0, 0, 0, 0, 56, 320, 367, 105, 3, 0, 0, 0, 0, 0, 0
Offset: 0

Views

Author

Gus Wiseman, Dec 19 2019

Keywords

Examples

			Triangle begins:
  1
  0  1
  0  2  0
  0  3  2  0
  0  5  4  0  0
  0  7 11  1  0  0
  0 11 20  6  0  0  0
  0 15 40 16  0  0  0  0
  0 22 68 40  3  0  0  0  0
  ...
Row n = 5 counts the following sets of multisets:
  {{5}}          {{1},{4}}        {{1},{2},{1,1}}
  {{1,4}}        {{2},{3}}
  {{2,3}}        {{1},{1,3}}
  {{1,1,3}}      {{1},{2,2}}
  {{1,2,2}}      {{2},{1,2}}
  {{1,1,1,2}}    {{3},{1,1}}
  {{1,1,1,1,1}}  {{1},{1,1,2}}
                 {{1,1},{1,2}}
                 {{2},{1,1,1}}
                 {{1},{1,1,1,1}}
                 {{1,1},{1,1,1}}
		

Crossrefs

Row sums are A261049.
Column k = 1 is A000041.
Multisets of multisets are A061260, with row sums A001970.
Sets of sets are A330462, with row sums A050342.
Multisets of sets are A285229, with row sums A089259.
Sets of disjoint sets are A330460, with row sums A294617.

Programs

  • Maple
    b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0, add(binomial(
           combinat[numbpart](i), j)*expand(b(n-i*j, i-1)*x^j), j=0..n/i)))
        end:
    T:= n-> (p-> seq(coeff(p, x, i), i=0..n))(b(n$2)):
    seq(T(n), n=0..14);  # Alois P. Heinz, Dec 30 2019
  • Mathematica
    ppl[n_,k_]:=Switch[k,0,{n},1,IntegerPartitions[n],_,Join@@Table[Union[Sort/@Tuples[ppl[#,k-1]&/@ptn]],{ptn,IntegerPartitions[n]}]];
    Table[Length[Select[ppl[n,2],And[UnsameQ@@#,Length[#]==k]&]],{n,0,10},{k,0,n}]
    (* Second program: *)
    b[n_, i_] := b[n, i] = If[n == 0, 1, If[i<1, 0, Sum[Binomial[
         PartitionsP[i], j]*Expand[b[n - i*j, i - 1]*x^j], {j, 0, n/i}]]];
    T[n_] := Function[p, Table[Coefficient[p, x, i], {i, 0, n}]][b[n, n]];
    T /@ Range[0, 14] // Flatten (* Jean-François Alcover, May 18 2021, after Alois P. Heinz *)
  • PARI
    A(n)={my(v=Vec(prod(k=1, n, (1 + x^k*y + O(x*x^n))^numbpart(k)))); vector(#v, n, Vecrev(v[n],n))}
    {my(T=A(12)); for(n=1, #T, print(T[n]))} \\ Andrew Howroyd, Dec 29 2019

Formula

G.f.: Product_{j>=1} (1 + y*x^j)^A000041(j). - Andrew Howroyd, Dec 29 2019

A336343 Number of ways to choose a strict partition of each part of a strict composition of n.

Original entry on oeis.org

1, 1, 1, 4, 6, 11, 26, 39, 78, 142, 320, 488, 913, 1558, 2798, 5865, 9482, 16742, 28474, 50814, 82800, 172540, 266093, 472432, 790824, 1361460, 2251665, 3844412, 7205416, 11370048, 19483502, 32416924, 54367066, 88708832, 149179800, 239738369, 445689392
Offset: 0

Views

Author

Gus Wiseman, Jul 19 2020

Keywords

Comments

A strict composition of n (A032020) is a finite sequence of distinct positive integers summing to n.
Is there a simple generating function?

Examples

			The a(1) = 1 through a(5) = 11 ways:
  (1)  (2)  (3)      (4)        (5)
            (2,1)    (3,1)      (3,2)
            (1),(2)  (1),(3)    (4,1)
            (2),(1)  (3),(1)    (1),(4)
                     (1),(2,1)  (2),(3)
                     (2,1),(1)  (3),(2)
                                (4),(1)
                                (1),(3,1)
                                (2,1),(2)
                                (2),(2,1)
                                (3,1),(1)
		

Crossrefs

Multiset partitions of partitions are A001970.
Strict compositions are counted by A032020, A072574, and A072575.
Splittings of strict partitions are A072706.
Set partitions of strict partitions are A294617.
Splittings of partitions with distinct sums are A336131.
Partitions:
- Partitions of each part of a partition are A063834.
- Compositions of each part of a partition are A075900.
- Strict partitions of each part of a partition are A270995.
- Strict compositions of each part of a partition are A336141.
Strict partitions:
- Partitions of each part of a strict partition are A271619.
- Compositions of each part of a strict partition are A304961.
- Strict partitions of each part of a strict partition are A279785.
- Strict compositions of each part of a strict partition are A336142.
Compositions:
- Partitions of each part of a composition are A055887.
- Compositions of each part of a composition are A133494.
- Strict partitions of each part of a composition are A304969.
- Strict compositions of each part of a composition are A307068.
Strict compositions:
- Partitions of each part of a strict composition are A336342.
- Compositions of each part of a strict composition are A336127.
- Strict partitions of each part of a strict composition are A336343.
- Strict compositions of each part of a strict composition are A336139.

Programs

  • Mathematica
    strptn[n_]:=Select[IntegerPartitions[n],UnsameQ@@#&];
    Table[Length[Join@@Table[Tuples[strptn/@ctn],{ctn,Join@@Permutations/@strptn[n]}]],{n,0,10}]
  • PARI
    \\ here Q(N) gives A000009 as a vector.
    Q(n) = {Vec(eta(x^2 + O(x*x^n))/eta(x + O(x*x^n)))}
    seq(n)={my(b=Q(n)); [subst(serlaplace(p),y,1) | p<-Vec(prod(k=1, n, 1 + y*x^k*b[1+k] + O(x*x^n)))]} \\ Andrew Howroyd, Apr 16 2021

Formula

G.f.: Sum_{k>=0} k! * [y^k](Product_{j>=1} 1 + y*x^j*A000009(j)). - Andrew Howroyd, Apr 16 2021

A330461 Array read by antidiagonals where A(n,k) is the number of multiset partitions with k levels that are strict at all levels and have total sum n.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 3, 1, 1, 1, 1, 3, 4, 4, 1, 1, 1, 1, 4, 7, 7, 5, 1, 1, 1, 1, 5, 12, 14, 11, 6, 1, 1, 1, 1, 6, 19, 29, 25, 16, 7, 1, 1, 1, 1, 8, 30, 57, 60, 41, 22, 8, 1, 1, 1, 1, 10, 49, 110, 141, 111, 63, 29, 9, 1, 1, 1
Offset: 0

Views

Author

Gus Wiseman, Dec 18 2019

Keywords

Examples

			Array begins:
       k=0 k=1 k=2 k=3 k=4 k=5 k=6
      -----------------------------
  n=0:  1   1   1   1   1   1   1
  n=1:  1   1   1   1   1   1   1
  n=2:  1   1   1   1   1   1   1
  n=3:  1   2   3   4   5   6   7
  n=4:  1   2   4   7  11  16  22
  n=5:  1   3   7  14  25  41  63
  n=6:  1   4  12  29  60 111 189
For example, the A(5,3) = 14 partitions are:
  {{5}}      {{1}}{{4}}
  {{14}}     {{2}}{{3}}
  {{23}}     {{1}}{{13}}
  {{1}{4}}   {{2}}{{12}}
  {{2}{3}}   {{1}}{{1}{3}}
  {{1}{13}}  {{2}}{{1}{2}}
  {{2}{12}}  {{1}}{{1}{12}}
		

Crossrefs

Columns are A000012 (k = 0), A000009 (k = 1), A050342 (k = 2), A050343 (k = 3), A050344 (k = 4).
The non-strict version is A290353.

Programs

  • Mathematica
    spl[n_,0]:={n};
    spl[n_,k_]:=Select[Join@@Table[Union[Sort/@Tuples[spl[#,k-1]&/@ptn]],{ptn,IntegerPartitions[n]}],UnsameQ@@#&];
    Table[Length[spl[n-k,k]],{n,0,10},{k,0,n}]
  • PARI
    WeighT(v)={Vec(exp(x*Ser(dirmul(v, vector(#v,n,(-1)^(n-1)/n))))-1,-#v)}
    M(n, k=n)={my(L=List(), v=vector(n,i,1)); listput(L, concat([1], v)); for(j=1, k, v=WeighT(v); listput(L, concat([1], v))); Mat(Col(L))~}
    { my(A=M(7)); for(i=1, #A, print(A[i,])) } \\ Andrew Howroyd, Dec 31 2019

Formula

Column k is the k-th weigh transform of the all-ones sequence. The weigh transform of a sequence b has generating function Product_{i > 0} (1 + x^i)^b(i).

A294787 Number of ways to choose a set partition of a factorization of n into distinct factors greater than one.

Original entry on oeis.org

1, 1, 1, 1, 1, 3, 1, 3, 1, 3, 1, 5, 1, 3, 3, 3, 1, 5, 1, 5, 3, 3, 1, 12, 1, 3, 3, 5, 1, 12, 1, 5, 3, 3, 3, 12, 1, 3, 3, 12, 1, 12, 1, 5, 5, 3, 1, 19, 1, 5, 3, 5, 1, 12, 3, 12, 3, 3, 1, 26, 1, 3, 5, 10, 3, 12, 1, 5, 3, 12, 1, 26, 1, 3, 5, 5, 3, 12, 1, 19, 3, 3
Offset: 1

Views

Author

Gus Wiseman, Nov 08 2017

Keywords

Crossrefs

Programs

  • Mathematica
    strfacs[n_]:=If[n<=1,{{}},Join@@Table[Map[Prepend[#,d]&,Select[strfacs[n/d],Min@@#>d&]],{d,Rest[Divisors[n]]}]];
    Table[Total[BellB/@Length/@strfacs[n]],{n,100}]

Formula

A294786(n) <= a(n) <= A294788(n).

A330759 Number T(n,k) of set partitions into k blocks of strict integer partitions of n; triangle T(n,k), n>=0, 0<=k<=A003056(n), read by rows.

Original entry on oeis.org

1, 0, 1, 0, 1, 0, 2, 1, 0, 2, 1, 0, 3, 2, 0, 4, 5, 1, 0, 5, 6, 1, 0, 6, 9, 2, 0, 8, 13, 3, 0, 10, 23, 10, 1, 0, 12, 27, 11, 1, 0, 15, 40, 19, 2, 0, 18, 51, 26, 3, 0, 22, 71, 40, 5, 0, 27, 100, 73, 16, 1, 0, 32, 127, 93, 19, 1, 0, 38, 163, 132, 31, 2, 0, 46, 215, 184, 45, 3
Offset: 0

Views

Author

Alois P. Heinz, Dec 29 2019

Keywords

Examples

			T(10,1) = 10: (10), 1234, 127, 136, 145, 19, 235, 28, 37, 46.
T(10,2) = 23: 123|4, 124|3, 12|34, 12|7, 134|2, 13|24, 13|6, 14|23, 14|5, 15|4, 16|3, 17|2, 1|234, 1|27, 1|36, 1|45, 1|9, 23|5, 25|3, 2|35, 2|8, 3|7, 4|6.
T(10,3) = 10: 12|3|4, 13|2|4, 14|2|3, 1|23|4, 1|24|3, 1|2|34, 1|2|7, 1|3|6, 1|4|5, 2|3|5.
T(10,4) = 1: 1|2|3|4.
Triangle T(n,k) begins:
  1;
  0,  1;
  0,  1;
  0,  2,   1;
  0,  2,   1;
  0,  3,   2;
  0,  4,   5,  1;
  0,  5,   6,  1;
  0,  6,   9,  2;
  0,  8,  13,  3;
  0, 10,  23, 10,  1;
  0, 12,  27, 11,  1;
  0, 15,  40, 19,  2;
  0, 18,  51, 26,  3;
  0, 22,  71, 40,  5;
  0, 27, 100, 73, 16, 1;
  ...
		

Crossrefs

Columns k=0-1 give: A000007, A000009 (for n>0).
Row sums give A294617.
Cf. A000041, A000096, A000217, A003056, A072706, A330460 (another version), A330765.

Programs

  • Maple
    b:= proc(n, i, k) option remember; `if`(i*(i+1)/2 b(n-i, t, k)*k
            +b(n-i, t, k+1))(min(n-i, i-1))))
        end:
    T:= n-> (p-> seq(coeff(p, x, i), i=0..degree(p)))(b(n$2, 0)):
    seq(T(n), n=0..20);
  • Mathematica
    b[n_, i_, k_] := b[n, i, k] = If[i(i+1)/2 < n, 0,
         If[n == 0, x^k, b[n, i-1, k] + With[{t = Min[n-i, i-1]},
         b[n-i, t, k]*k + b[n-i, t, k+1]]]];
    T[n_] := CoefficientList[b[n, n, 0], x];
    T /@ Range[0, 20] // Flatten (* Jean-François Alcover, Mar 12 2021, after Alois P. Heinz *)

Formula

Sum_{k=0..2} T(n,k) = A072706(n).
Sum_{k=1..A003056(n)} k * T(n,k) = A330765(n).
T(A000217(n),n) = 1.
T(A000096(n),n) = A000041(n).
T(n*(n+1)/2+j,n) = A000041(j) for 0 <= j <= n.

A320886 Number of multiset partitions of integer partitions of n where all parts have the same product.

Original entry on oeis.org

1, 1, 3, 5, 10, 14, 25, 33, 54, 73, 107, 140, 207, 264, 369, 479, 652, 828, 1112, 1400, 1848, 2326, 3009, 3762, 4856, 6020, 7648, 9478, 11942, 14705, 18427, 22576, 28083, 34350, 42429, 51714, 63680, 77289, 94618, 114648, 139773, 168799, 205144, 247128, 299310, 359958, 434443, 521255, 627812, 751665, 902862
Offset: 0

Views

Author

Gus Wiseman, Oct 23 2018

Keywords

Examples

			The a(1) = 1 through a(6) = 25 multiset partitions:
  (1)  (2)     (3)        (4)           (5)              (6)
       (11)    (12)       (13)          (14)             (15)
       (1)(1)  (111)      (22)          (23)             (24)
               (1)(11)    (112)         (113)            (33)
               (1)(1)(1)  (1111)        (122)            (114)
                          (2)(2)        (1112)           (123)
                          (1)(111)      (11111)          (222)
                          (11)(11)      (2)(12)          (1113)
                          (1)(1)(11)    (1)(1111)        (1122)
                          (1)(1)(1)(1)  (11)(111)        (3)(3)
                                        (1)(1)(111)      (11112)
                                        (1)(11)(11)      (111111)
                                        (1)(1)(1)(11)    (12)(12)
                                        (1)(1)(1)(1)(1)  (2)(112)
                                                         (2)(2)(2)
                                                         (1)(11111)
                                                         (11)(1111)
                                                         (111)(111)
                                                         (1)(1)(1111)
                                                         (1)(11)(111)
                                                         (11)(11)(11)
                                                         (1)(1)(1)(111)
                                                         (1)(1)(11)(11)
                                                         (1)(1)(1)(1)(11)
                                                         (1)(1)(1)(1)(1)(1)
		

Crossrefs

Programs

  • Mathematica
    sps[{}]:={{}};sps[set:{i_,_}]:=Join@@Function[s,Prepend[#,s]&/@sps[Complement[set,s]]]/@Cases[Subsets[set],{i,_}];
    mps[set_]:=Union[Sort[Sort/@(#/.x_Integer:>set[[x]])]&/@sps[Range[Length[set]]]];
    Table[Length[Select[Join@@mps/@IntegerPartitions[n],SameQ@@Times@@@#&]],{n,8}]
  • PARI
    G(n)={my(M=Map()); for(k=1, n, forpart(p=k, my(t=vecprod(Vec(p)), z); mapput(M, t, if(mapisdefined(M, t, &z), z, 0) + x^k))); M}
    a(n)=if(n==0, 1, vecsum(apply(p->EulerT(Vecrev(p/x, n))[n], Mat(G(n))[,2]))) \\ Andrew Howroyd, Oct 26 2018

Extensions

a(13)-a(50) from Andrew Howroyd, Oct 26 2018

A336140 Number of ways to choose a set partition of the parts of a strict integer composition of n.

Original entry on oeis.org

1, 1, 1, 5, 5, 9, 39, 43, 73, 107, 497, 531, 951, 1345, 2125, 8789, 9929, 16953, 24723, 38347, 52717, 219131, 240461, 419715, 600075, 938689, 1278409, 1928453, 6853853, 7815657, 13205247, 19051291, 29325121, 40353995, 60084905, 80722899, 277280079, 312239953
Offset: 0

Views

Author

Gus Wiseman, Jul 16 2020

Keywords

Comments

A strict composition of n is a finite sequence of distinct positive integers summing to n.

Crossrefs

Set partitions are A000110.
Strict compositions are A032020.
Set partitions of binary indices are A050315.
Set partitions of strict partitions are A294617.

Programs

  • Maple
    b:= proc(n, i, p) option remember; `if`(i*(i+1)/2 b(n$2, 0):
    seq(a(n), n=0..40);  # Alois P. Heinz, Jul 30 2020
  • Mathematica
    Table[Sum[BellB[Length[ctn]],{ctn,Join@@Permutations/@Select[ IntegerPartitions[n],UnsameQ@@#&]}],{n,0,10}]
    (* Second program: *)
    b[n_, i_, p_] := b[n, i, p] = If[i(i+1)/2 < n, 0, If[n == 0,
         BellB[p]*p!, b[n, i-1, p] + b[n-i, Min[n-i, i-1], p+1]]];
    a[n_] := b[n, n, 0];
    a /@ Range[0, 40] (* Jean-François Alcover, May 21 2021, after Alois P. Heinz *)

Formula

a(n) = Sum_{k = 0..n} A000110(k) * A072574(n,k) = Sum_{k = 0..n} k! * A000110(k) * A008289(n,k).

A356957 Number of set partitions of strict integer partitions of n into intervals, where an interval is a set of positive integers with all differences of adjacent elements equal to 1.

Original entry on oeis.org

1, 1, 1, 3, 2, 4, 7, 7, 8, 13, 20, 19, 27, 30, 42, 60, 63, 75, 99, 112, 141, 191, 205, 248, 296, 357, 408, 513, 617, 696, 831, 969, 1117, 1337, 1523, 1797, 2171, 2420, 2805, 3265, 3772, 4289, 5013, 5661, 6579, 7679, 8615, 9807, 11335, 12799, 14581
Offset: 0

Views

Author

Gus Wiseman, Sep 13 2022

Keywords

Examples

			The a(1) = 1 through a(6) = 7 set partitions:
  {{1}}  {{2}}  {{3}}      {{4}}      {{5}}      {{6}}
                {{1,2}}    {{1},{3}}  {{2,3}}    {{1,2,3}}
                {{1},{2}}             {{1},{4}}  {{1},{5}}
                                      {{2},{3}}  {{2},{4}}
                                                 {{1},{2,3}}
                                                 {{1,2},{3}}
                                                 {{1},{2},{3}}
		

Crossrefs

Intervals are counted by A000012, A001227, ranked by A073485.
The initial version is A010054.
For set partitions of {1..n} we have A011782.
The non-strict version is A107742
Not restricting to intervals gives A294617.
A000041 counts integer partitions, strict A000009.
A000110 counts set partitions.
A001970 counts multiset partitions of integer partitions.
A356941 counts multiset partitions of integer partitions w/ gapless blocks.

Programs

  • Mathematica
    chQ[y_] := Length[y] <= 1 || Union[Differences[y]] == {1};
    sps[{}]:={{}};sps[set:{i_,_}]:=Join@@Function[s,Prepend[#,s]&/@sps[Complement[set,s]]]/@Cases[Subsets[set],{i,_}];
    Table[Length[Select[Join@@sps/@Reverse/@Select[IntegerPartitions[n], UnsameQ@@#&],And@@chQ/@#&]],{n,0,15}]

A376263 Number of strict integer compositions of n whose leaders of increasing runs are increasing.

Original entry on oeis.org

1, 1, 1, 2, 2, 3, 5, 6, 8, 11, 18, 21, 30, 38, 52, 77, 96, 126, 167, 217, 278, 402, 488, 647, 822, 1073, 1340, 1747, 2324, 2890, 3695, 4690, 5924, 7469, 9407, 11718, 15405, 18794, 23777, 29507, 37188, 45720, 57404, 70358, 87596, 110672, 135329, 167018, 206761, 254200, 311920
Offset: 0

Views

Author

Gus Wiseman, Sep 18 2024

Keywords

Comments

The leaders of increasing runs of a sequence are obtained by splitting it into maximal increasing subsequences and taking the first term of each.

Examples

			The a(1) = 1 through a(9) = 11 compositions:
 (1) (2) (3)   (4)   (5)   (6)     (7)     (8)     (9)
         (1,2) (1,3) (1,4) (1,5)   (1,6)   (1,7)   (1,8)
                     (2,3) (2,4)   (2,5)   (2,6)   (2,7)
                           (1,2,3) (3,4)   (3,5)   (3,6)
                           (1,3,2) (1,2,4) (1,2,5) (4,5)
                                   (1,4,2) (1,3,4) (1,2,6)
                                           (1,4,3) (1,3,5)
                                           (1,5,2) (1,5,3)
                                                   (1,6,2)
                                                   (2,3,4)
                                                   (2,4,3)
		

Crossrefs

For less-greater or greater-less we have A294617.
This is a strict case of A374688, weak version A374635.
The strict less-greater version is A374689, weak version A189076.
A003242 counts anti-run compositions, ranks A333489.
A011782 counts compositions, strict A032020.
A238130, A238279, A333755 count compositions by number of runs.
A373949 counts compositions by run-compressed sum, opposite A373951.
A374700 counts compositions by sum of leaders of strictly increasing runs.

Programs

  • Mathematica
    Table[Length[Select[Join@@Permutations/@IntegerPartitions[n], UnsameQ@@#&&Less@@First/@Split[#,Less]&]],{n,0,15}]
  • PARI
    \\ here Q(n) gives n-th row of A008289.
    Q(n)={Vecrev(polcoef(prod(k=1, n, 1 + y*x^k, 1 + O(x*x^n)), n)/y)}
    a(n)={if(n==0, 1, my(r=Q(n), s=Vec(serlaplace(exp(exp(x+O(x^#r))- 1)))); sum(k=1, #r, r[k]*s[k]))} \\ Andrew Howroyd, Sep 18 2024

Formula

a(n) = Sum_{k>=1} A008289(n,k)*A000110(k-1) for n > 0. - Andrew Howroyd, Sep 18 2024

Extensions

a(26) onwards from Andrew Howroyd, Sep 18 2024

A374932 Number T(n,k) of partitions of [n] such that the maximal block element sum equals k; triangle T(n,k), n>=0, n <= k <= A000217(n), read by rows.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 1, 3, 3, 3, 3, 1, 1, 1, 6, 6, 8, 9, 9, 5, 3, 3, 1, 1, 1, 12, 14, 20, 31, 26, 32, 19, 14, 11, 10, 5, 3, 3, 1, 1, 1, 26, 31, 59, 78, 111, 108, 113, 76, 67, 57, 39, 39, 21, 16, 12, 10, 5, 3, 3, 1, 1, 1, 57, 84, 140, 260, 321, 458, 427, 500, 326, 300, 284, 229, 182, 159, 107, 79, 64, 46, 41, 23, 17, 12, 10, 5, 3, 3, 1, 1, 1
Offset: 0

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Author

Alois P. Heinz, Aug 01 2024

Keywords

Examples

			T(5,7) = 8: 124|3|5, 12|34|5, 13|25|4, 14|25|3, 15|2|34, 1|25|34, 1|2|34|5, 1|25|3|4.
T(6,6) = 12: 123|4|5|6, 12|3|4|5|6, 13|24|5|6, 13|2|4|5|6, 14|23|5|6, 15|23|4|6, 1|23|4|5|6, 14|2|3|5|6, 15|24|3|6, 1|24|3|5|6, 15|2|3|4|6, 1|2|3|4|5|6.
T(6,7) = 14: 124|3|5|6, 12|34|5|6, 13|25|4|6, 16|23|4|5, 14|25|3|6, 16|24|3|5, 15|2|34|6, 16|25|34, 1|25|34|6, 16|2|34|5, 1|2|34|5|6, 16|25|3|4, 1|25|3|4|6, 16|2|3|4|5.
Triangle T(n,k) begins:
  1;
     1;
        1, 1;
           2, 1, 1,  1;
              3, 3,  3,  3,  1,  1,  1;
                 6,  6,  8,  9,  9,  5,  3,  3,  1,  1,  1;
                    12, 14, 20, 31, 26, 32, 19, 14, 11, 10, 5, 3, 3, 1, 1, 1;
                    ...
		

Crossrefs

Row sums give A000110.
Main diagonal gives A375099.
Number of terms in row n is A000124(n-1) for n>=1.
Reversed rows converge to A294617.
Cf. A000217.
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