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 1-5 of 5 results.

A174713 Triangle read by rows, A173305 (A000009 shifted down twice) * A174712 (diagonalized variant of A000041).

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 2, 1, 2, 3, 2, 2, 4, 2, 2, 3, 5, 3, 4, 3, 6, 4, 4, 3, 5, 8, 5, 6, 6, 5, 10, 6, 8, 6, 5, 7, 12, 8, 10, 9, 10, 7, 15, 10, 12, 12, 10, 7, 11, 18, 12, 16, 15, 15, 14, 11, 22, 15, 20, 18, 20, 14, 11, 15
Offset: 0

Views

Author

Gary W. Adamson, Mar 27 2010

Keywords

Comments

Row sums = A000041, the partition numbers.
The current triangle is the 2nd in an infinite set, followed by A174714 (k=3), and A174715, (k=4); in which row sums of each triangle = A000041.
k-th triangle in the infinite set can be defined as having the sequence:
"Euler transform of ones: (1,1,1,...) interleaved with (k-1) zeros"; shifted down k times (except column 0) in successive columns, then multiplied * triangle A174712, the diagonalized variant of A000041, A174713 begins with A000009 shifted down twice (triangle A173305); where A000009 = the Euler transform of period 2 sequence: [1,0,1,0,...].
Similarly, triangle A174714 begins with A000716 shifted down thrice; where A000716 = the Euler transform of period 3 series: [1,1,0,1,1,0,...]. Then multiply the latter as an infinite lower triangular matrix * A174712, the diagonalized variant of A000041, obtaining triangle A174714 with row sums = A000041.
Case k=4 = triangle A174715 which begins with the Euler transform of period 4 series: [1,1,1,0,1,1,1,0,...], shifted down 4 times in successive columns then multiplied * A174712, the diagonalized variant of A000041.
All triangles in the infinite set have row sums = A000041.
The sequences: "Euler transform of ones interleaved with (k-1) zeros" have the following properties, beginning with k=2:
...
k=2, A000009: = Euler transform of [1,0,1,0,1,0,...] and satisfies
.....A000009. = p(x)/p(x^2), where p(x) = polcoeff A000041; and A000041 =
.....A000009(x) = r(x), then p(x) = r(x) * r(x^2) * r(x^4) * r(x^8) * ...
...
k=3, A000726: = Euler transform of [1,1,0,1,1,0,...] and satisfies
.....A000726(x): = p(x)/p(x^3), and given s(x) = polcoeff A000726, we get
.....A000041(x) = p(x) = s(x) * s(x^3) * s(x^9) * s(x^27) * ...
...
k=4, A001935: = Euler transform of [1,1,1,0,1,1,1,0,...] and satisfies
.....A001935(x) = p(x)/p(x^4) and given t(x) = polcoeff A001935, we get
.....A000041(x) = p(x) = t(x) * t(x^4) * t(x^16) * t(x^64) * ...
...
Also the number of integer partitions of n whose even parts sum to k, for k an even number from zero to n. The version including odd k is A113686. - Gus Wiseman, Oct 23 2023

Examples

			First few rows of the triangle =
1;
1;
1, 1;
2, 1;
2, 1, 2;
3, 2, 2;
4, 2, 2, 3;
5, 3, 4, 3;
6, 4, 4, 3, 5;
8, 5, 6, 6, 5;
10, 6, 8, 6, 5, 7;
12, 8, 10, 9, 10, 7;
15, 10, 12, 12, 10, 7, 11;
18, 12, 16, 15, 15, 14, 11;
22, 15, 20, 18, 20, 14, 11, 15;
...
From _Gus Wiseman_, Oct 23 2023: (Start)
Row n = 9 counts the following partitions:
  (9)          (72)        (54)       (63)      (81)
  (711)        (5211)      (522)      (6111)    (621)
  (531)        (3321)      (4311)     (432)     (441)
  (51111)      (321111)    (411111)   (42111)   (4221)
  (333)        (21111111)  (32211)    (3222)    (22221)
  (33111)                  (2211111)  (222111)
  (3111111)
  (111111111)
(End)
		

Crossrefs

Row sums are A000041.
The odd version is A365067.
The corresponding rank statistic is A366531, odd version A366528.
A000009 counts partitions into odd parts, ranks A066208.
A113685 counts partitions by sum of odd parts, even version A113686.
A239261 counts partitions with (sum of odd parts) = (sum of even parts).

Programs

  • Mathematica
    Table[Length[Select[IntegerPartitions[n],Total[Select[#,EvenQ]]==k&]],{n,0,15},{k,0,n,2}] (* Gus Wiseman, Oct 23 2023 *)

Formula

As infinite lower triangular matrices, A173305 * A174712.
T(n,k) = A000009(n-2k) * A000041(k). - Gus Wiseman, Oct 23 2023

A174714 Triangle read by rows, Q*M; Q = an infinite lower triangular matrix with A000726 shifted down thrice, M = triangle A174712, the diagonalized variant of A000041.

Original entry on oeis.org

1, 1, 2, 2, 1, 4, 1, 5, 2, 7, 2, 2, 9, 4, 2, 13, 5, 4, 16, 7, 4, 3, 22, 9, 8, 3, 27, 13, 10, 6, 36, 16, 14, 6, 5, 44, 22, 18, 12, 5, 57, 27, 26, 15, 10
Offset: 0

Views

Author

Gary W. Adamson, Mar 27 2010

Keywords

Comments

Refer to comments in A174713.
Row sums = A000041, the partition numbers.

Examples

			First few rows of the triangle =
1;
1;
2;
2, 1;
4, 1;
5, 2;
7, 2, 2;
9, 4, 2;
13, 5, 4;
16, 7, 4, 3;
22, 9, 8, 3;
27, 13, 10, 6;
36, 16, 14, 6, 5;
44, 22, 18, 12, 5;
57, 27, 26, 15, 10;
...
		

Crossrefs

Formula

Let Q = an infinite lower triangular matrix with A000726, (Euler transform of [1,1,0,1,1,0,...]) in each column shifted down thrice from the (k-1)-th column, excepting column 0. Let M = triangle A174712, the diagonalized variant of A000041. Then triangle A174714 = Q*M.

A174715 Triangle read by rows, Q*M as infinite lower triangular matrices. Q = A001935 shifted down four times by columns, M = A174712.

Original entry on oeis.org

1, 1, 2, 3, 4, 1, 6, 1, 9, 2, 12, 3, 16, 4, 2, 22, 6, 2, 29, 9, 4, 38, 12, 6, 50, 16, 8, 3, 64, 22, 12, 3, 82, 29, 18, 6
Offset: 0

Views

Author

Gary W. Adamson, Mar 27 2010

Keywords

Comments

Row sums = A000041, the partition numbers.
Refer to comments in A174713.

Examples

			First few rows of the triangle =
  1;
  1;
  2;
  3;
  4, 1;
  6, 1;
  9, 2;
  12, 3;
  16, 4, 2;
  22, 6, 2;
  29, 9, 4;
  38, 12, 6;
  50, 16, 8, 3;
  64, 22, 12, 3;
  82, 29, 18, 6;
  ...
		

Crossrefs

Formula

As an irregular triangle generated from a product Q*M of infinite lower triangular matrices: Q = A001935 in every column (except column 0), shifted down four times from the previous column. M = A174712, the diagonalized variant of A000041 (the partition numbers as the right border, and the rest zeros.)

A174739 Triangle read by rows, a partition number generator; A145006 * the diagonalized variant of A000041, (A174712).

Original entry on oeis.org

1, 1, 1, 0, 1, 2, 0, 0, 2, 3, -1, 0, 0, 3, 5, 0, -1, 0, 0, 5, 7, -1, 0, -2, 0, 0, 7, 11, 0, -1, 0, -3, 0, 0, 11, 15, 0, 0, -2, 0, -5, 0, 15, 22, 0, 0, 0, -3, 0, -7, 0, 0, 22, 30, 0, 0, 0, 0, -5, 0, -11, 0, 0, 30, 42, 1, 0, 0, 0, 0, -7, 0, -15, 0, 0, 42, 56, 0, 1, 0, 0, 0, 0, -11, 0, -22, 0, 0, 0, 0
Offset: 1

Views

Author

Gary W. Adamson, Mar 28 2010

Keywords

Comments

Row sums = the partition numbers, A000041 starting with offset 1.
The triangle demonstrates an equivalency to Euler's pentagonal recurrence
relation, such that sum of n-th row terms = rightmost term of next row, a
partition number.
Contribution from Gary W. Adamson, Mar 28 2010: (Start)
A174739 is equivalent to Euler's pentagonal theorem in triangular form.
For example, row 9 = (0, 0, -2, 0, -5, 0, 0, 15, 22) or: p(9) = 30 = p(8)
+ p(7) - p(4) - p(2). (End)

Examples

			First few rows of the triangle =
1;
1, 1;
0, 1, 2;
0, 0, 2, 3;
-1, 0, 0, 3, 5;
0, -1, 0, 0, 5, 7;
-1, 0, -2, 0, 0, 7, 11;
0, -1, 0, -3, 0, 0, 11, 15;
0, 0, -2, 0, -5, 0, 0, 15, 22;
0, 0, 0, -3, 0, -7, 0, 0, 22, 30;
0, 0, 0, 0, -5, 0, -11, 0, 0, 30, 42;
1, 0, 0, 0, 0, -7, 0, -15, 0, 0, 42, 56;
0, 1, 0, 0, 0, 0, -11, 0, 22, 0, 0, 56, 77;
0, 0, 2, 0, 0, 0, 0, -15, 0, -30, 0, 0, 77, 101;
1, 0, 0, 3, 0, 0, 0, 0, -22, 0, -42, 0, 0, 101, 135;
0, 1, 0, 0, 5, 0, 0, 0, 0, -30, 0, -56, 0, 0, 135, 176;
0, 0, 2, 0, 0, 7, 0, 0, 0, 0, -42, 0, -77, 0, 0, 176, 231;
0, 0, 0, 3, 0, 0, 11, 0, 0, 0, 0, -56, 0, -101, 0, 0, 231, 297;
...
		

Crossrefs

Formula

Given triangle A145006, delete the first "1", = triangle Q. With M = A174712,
the diagonalize variant of the partition numbers, perform Q*M as infinite lower
triangular matrices.

A058694 Partial products p(0)*p(1)*...*p(n) of partition numbers A000041.

Original entry on oeis.org

1, 1, 2, 6, 30, 210, 2310, 34650, 762300, 22869000, 960498000, 53787888000, 4141667376000, 418308404976000, 56471634671760000, 9939007702229760000, 2295910779215074560000, 681885501426877144320000, 262525918049347700563200000, 128637699844180373275968000000
Offset: 0

Views

Author

N. J. A. Sloane, Dec 30 2000

Keywords

Comments

a(n) gives the number of partitions P(V(n)) of V(n)=[1,2,3,...,n]. A partition P(V(n)) acts on the components of V(n), i.e., the components of V(n) are partitioned. Therefore a(n) results as the product of the number of partitions P(i) of the component v(i)=i with i=1,...,n. For example, a(3) = 6 because we have 6 list partitions for the list V(n=3)=[1,2,3]: [[1], [1, 1], [2, 1]], [[1], [1, 1], [1, 1, 1]], [[1], [1, 1], [3]], [[1], [2], [2, 1]], [[1], [2], [1, 1, 1]], [[1], [2], [3]]. - Thomas Wieder, Sep 29 2007
Equals the eigensequence of triangle A174712; i.e., Triangle A174712 * A058694 preceded by a 1 shifts left. - Gary W. Adamson, Mar 27 2010

Crossrefs

Programs

  • Maple
    a:= proc(n) option remember;
           combinat[numbpart](n)*`if`(n>0, a(n-1), 1)
        end:
    seq(a(n), n=0..40);  # Alois P. Heinz, Apr 21 2012
    #
    # The constant S in the Maple notation
    evalf(Zeta(0, -1/2, 23/24)*sqrt(2/3)*Pi - Zeta(0, 1/2, 23/24)*sqrt(3/2)/Pi+3*(D(GAMMA))(23/24)/(4*Pi^2*GAMMA(23/24)) - (Sum(Zeta(0, j/2, 23/24)*(sqrt(3/2)/Pi)^j/j, j=3..infinity)), 60); # Vaclav Kotesovec, Jun 24 2015
  • Mathematica
    Table[Product[PartitionsP[k], {k, 1, n}], {n, 1, 33}] (* Vladimir Joseph Stephan Orlovsky, Dec 13 2008 *)
  • PARI
    a(n)=prod(k=2,n, numbpart(k)) \\ Charles R Greathouse IV, Jan 14 2017

Formula

a(n) ~ C * Product_{k=1..n} (exp(Pi*sqrt(2/3*(k-1/24))) / (4*sqrt(3)*(k-1/24)) * (1 - sqrt(3/(2*(k-1/24)))/Pi)), where C = 0.9110167313322499518... is the partition factorial constant A259314. - Vaclav Kotesovec, Jun 24 2015
a(n) ~ C * Gamma(23/24) / (n^(n + 11/24 + 3/(4*Pi^2)) * 2^(2*n) * 3^(n/2) * sqrt(2*Pi)) * exp(Pi*(2*n/3)^(3/2) + n + (11*Pi/(12*sqrt(6)) - sqrt(6)/Pi)*sqrt(n) + S), where C = A259314 and S = Zeta(-1/2, 23/24)*sqrt(2/3)*Pi - Zeta(1/2, 23/24)*sqrt(3/2)/Pi + 3*Gamma'(23/24)/(4*Pi^2*Gamma(23/24)) - Sum_{j>=3} Zeta(j/2, 23/24)*(sqrt(3/2)/Pi)^j/j = -0.02541933397793652709903012019225640813047573968579474..., Zeta is the Hurwitz Zeta Function, in Maple notation Zeta(0,z,v), in Mathematica notation Zeta[z,v], equivalently HurwitzZeta[z,v]. - Vaclav Kotesovec, Jun 24 2015
Showing 1-5 of 5 results.