A179862 -id:A179862 - cp's OEIS frontend

A220517 First differences of A225600. Also A141285 and A194446 interleaved.

1, 1, 2, 2, 3, 3, 2, 1, 4, 5, 3, 1, 5, 7, 2, 1, 4, 2, 3, 1, 6, 11, 3, 1, 5, 2, 4, 1, 7, 15, 2, 1, 4, 2, 3, 1, 6, 4, 5, 1, 4, 1, 8, 22, 3, 1, 5, 2, 4, 1, 7, 4, 3, 1, 6, 2, 5, 1, 9, 30, 2, 1, 4, 2, 3, 1, 6, 4, 5, 1, 4, 1, 8, 7, 4, 1, 7, 2, 6, 1, 5, 1, 10, 42

Offset: 1

Omar E. Pol, Feb 07 2013

Number of toothpicks added at n-th stage to the toothpick structure (related to integer partitions) of A225600.

			Written as an irregular triangle in which row n has length 2*A187219(n) we can see that the right border gives A000041 and the previous term of the last term in row n is n.
1,1;
2,2;
3,3;
2,1,4,5;
3,1,5,7;
2,1,4,2,3,1,6,11;
3,1,5,2,4,1,7,15;
2,1,4,2,3,1,6,4,5,1,4,1,8,22;
3,1,5,2,4,1,7,4,3,1,6,2,5,1,9,30;
2,1,4,2,3,1,6,4,5,1,4,1,8,7,4,1,7,2,6,1,5,1,10,42;
.
Illustration of the first seven rows of triangle as a minimalist diagram of regions of the set of partitions of 7:
.      _ _ _ _ _ _ _
. 15   _ _ _ _      |
.      _ _ _ _|_    |
.      _ _ _    |   |
.      _ _ _|_ _|_  |
. 11   _ _ _      | |
.      _ _ _|_    | |
.      _ _    |   | |
.      _ _|_ _|_  | |
.  7   _ _ _    | | |
.      _ _ _|_  | | |
.  5   _ _    | | | |
.      _ _|_  | | | |
.  3   _ _  | | | | |
.  2   _  | | | | | |
.  1    | | | | | | |
.
.      1 2 3 4 5 6 7
.
Also using the elements of this diagram we can draw a Dyck path in which the n-th odd-indexed segment has A141285(n) up-steps and the n-th even-indexed segment has A194446(n) down-steps. Note that the height of the n-th largest peak between two valleys at height 0 is also the partition number A000041(n). See below:
.
7..................................
.                                 /\
5....................            /  \                /\
.                   /\          /    \          /\  /
3..........        /  \        /      \        /  \/
2.....    /\      /    \    /\/        \      /
1..  /\  /  \  /\/      \  /            \  /\/
0 /\/  \/    \/          \/              \/
. 0,2,  6,   12,         24,             40... = A211978
.  1, 4,   9,       19,           33... = A179862
.

Omar E. Pol, Visualization of regions in a minimalist diagram for A006128
N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS
Index entries for sequences related to toothpick sequences

Cf. A000041, A006128, A135010, A138137, A141285, A179862, A186114, A186412, A187219, A194446, A206437, A211978, A220517, A225600, A225610.

a(2n-1) = A141285(n); a(2n) = A194446(n), n >= 1

A330375 Irregular triangle read by rows: T(n,k) (n>=1) is the sum of the lengths of all k-th right angles in all partitions of n.

Original entry on oeis.org

1, 4, 9, 19, 1, 33, 2, 59, 7, 93, 12, 150, 26, 226, 43, 1, 342, 76, 2

Offset: 1

Omar E. Pol, Dec 21 2019

Column k starts in row k^2.

It appears that column 1 gives A179862.

			Triangle begins:
    1;
    4;
    9;
   19,  1;
   33,  2;
   59,  7;
   93, 12;
  150, 26;
  226, 43, 1;
  342, 76, 2;
...
Figure 1 shows the Ferrers diagram of the partition of 24: [7, 6, 3, 3, 2, 1, 1, 1]. Figure 2 shows the right-angles diagram of the same partition. Note that in this last diagram we can see the size of the three right angles as follows: the first right angle has size 14 because it contains 14 square cells, the second right angle has size 8 and the third right angle has size 2.
.
.                                     Right-angles   Right
Part   Ferrers diagram         Part   diagram        angle
                                      _ _ _ _ _ _ _
  7    * * * * * * *             7   |  _ _ _ _ _ _|  14
  6    * * * * * *               6   | |  _ _ _ _|     8
  3    * * *                     3   | | | |           2
  3    * * *                     3   | | |_|
  2    * *                       2   | |_|
  1    *                         1   | |
  1    *                         1   | |
  1    *                         1   |_|
.
       Figure 1.                      Figure 2.
.
For n = 8 the partitions of 8 and their respective right-angles diagrams are as follows:
.
    _       _ _       _ _ _       _ _ _ _       _ _ _ _ _
  1| |8   2|  _|8   3|  _ _|8   4|  _ _ _|8   5|  _ _ _ _|8
  1| |    1| |      1| |        1| |          1| |
  1| |    1| |      1| |        1| |          1| |
  1| |    1| |      1| |        1| |          1|_|
  1| |    1| |      1| |        1|_|
  1| |    1| |      1|_|
  1| |    1|_|
  1|_|
    _ _ _ _ _ _       _ _ _ _ _ _ _       _ _ _ _ _ _ _ _
  6|  _ _ _ _ _|8   7|  _ _ _ _ _ _|8   8|_ _ _ _ _ _ _ _|8
  1| |              1|_|
  1|_|
.
    _ _       _ _ _       _ _ _ _       _ _ _ _ _       _ _ _ _ _ _
  2|  _|7   3|  _ _|7   4|  _ _ _|7   5|  _ _ _ _|7   6|  _ _ _ _ _|7
  2| |_|1   2| |_|  1   2| |_|    1   2| |_|      1   2|_|_|        1
  1| |      1| |        1| |          1|_|
  1| |      1| |        1|_|
  1| |      1|_|
  1|_|
.
    _ _       _ _ _       _ _ _       _ _ _ _       _ _ _ _       _ _ _ _ _
  2|  _|6   3|  _ _|6   3|  _ _|6   4|  _ _ _|6   4|  _ _ _|6   5|  _ _ _ _|6
  2| | |2   2| | |  2   3| |_ _|2   2| | |    2   3| |_ _|  2   3|_|_ _|    2
  2| |_|    2| |_|      1| |        2|_|_|        1|_|
  1| |      1|_|        1|_|
  1|_|
.
    _ _       _ _ _        _ _ _ _
  2|  _|5   3|  _ _|5    4|  _ _ _|5
  2| | |3   3| |  _|3    4|_|_ _ _|3
  2| | |    2|_|_|
  2|_|_|
.
The sum of the lengths of the first right angles of all partitions of 8 is 8 + 8 + 8 + 8 + 8 + 8 + 8 + 8 + 7 + 7 + 7 + 7 + 7 + 6 + 6 + 6 + 6 + 6 + 6 + 5 + 5 + 5 = 150, so T(8,1) = 150.
The sum of the second right angles of all partitions of 8 is 1 + 1 + 1 + 1 + 1 + 2 + 2 + 2 + 2 + 2 + 2 + 3 + 3 + 3 = 26, so T(8,2) = 26.

Row sums give A066186.
Cf. A179862.
Cf. also A000041, A330369, A330378, A330379.

A330379 Triangle read by rows: T(n,k) (1 <= k <= n) is the sum of the sizes of all right angles of size k of all partitions of n.

Original entry on oeis.org

1, 0, 4, 0, 0, 9, 1, 0, 3, 16, 2, 0, 0, 8, 25, 3, 4, 0, 8, 15, 36, 4, 8, 0, 0, 20, 24, 49, 5, 12, 9, 0, 15, 36, 35, 64, 7, 16, 21, 0, 5, 36, 56, 48, 81, 9, 20, 33, 16, 0, 36, 63, 80, 63, 100, 13, 24, 45, 40, 0, 12, 77, 96, 108, 80, 121

Offset: 1

Omar E. Pol, Dec 31 2019

Observation: at least the first 11 terms of column 1 coincide with A188674 (using the same indices).

			Triangle begins:
   1;
   0,  4;
   0,  0,  9;
   1,  0,  3, 16;
   2,  0,  0,  8, 25;
   3,  4,  0,  8, 15, 36;
   4,  8,  0,  0, 20, 24, 49;
   5, 12,  9,  0, 15, 36, 35, 64;
   7, 16, 21,  0,  5, 36, 56, 48,  81;
   9, 20, 33, 16,  0, 36, 63, 80,  63, 100;
  13, 24, 45, 40,  0, 12, 77, 96, 108,  80, 121;
...
Below the figure 1 shows the Ferrers diagram of the partition of 24: [7, 6, 3, 3, 2, 1, 1, 1]. The figure 2 shows the right-angles diagram of the same partition. Note that in this last diagram we can see the size of the three right angles as follows: the first right angle has size 14 because it contains 14 square cells, the second right angle has size 8 and the third right angle has size 2.
.
.                                     Right-angles   Right
Part   Ferrers diagram         Part   diagram        angle
                                      _ _ _ _ _ _ _
  7    * * * * * * *             7   |  _ _ _ _ _ _|  14
  6    * * * * * *               6   | |  _ _ _ _|     8
  3    * * *                     3   | | | |           2
  3    * * *                     3   | | |_|
  2    * *                       2   | |_|
  1    *                         1   | |
  1    *                         1   | |
  1    *                         1   |_|
.
       Figure 1.                      Figure 2.
.
For n = 8 the partitions of 8 and their respective right-angles diagrams look as shown below:
.
    _       _ _       _ _ _       _ _ _ _       _ _ _ _ _
  1| |8   2|  _|8   3|  _ _|8   4|  _ _ _|8   5|  _ _ _ _|8
  1| |    1| |      1| |        1| |          1| |
  1| |    1| |      1| |        1| |          1| |
  1| |    1| |      1| |        1| |          1|_|
  1| |    1| |      1| |        1|_|
  1| |    1| |      1|_|
  1| |    1|_|
  1|_|
    _ _ _ _ _ _       _ _ _ _ _ _ _       _ _ _ _ _ _ _ _
  6|  _ _ _ _ _|8   7|  _ _ _ _ _ _|8   8|_ _ _ _ _ _ _ _|8
  1| |              1|_|
  1|_|
.
    _ _       _ _ _       _ _ _ _       _ _ _ _ _       _ _ _ _ _ _
  2|  _|7   3|  _ _|7   4|  _ _ _|7   5|  _ _ _ _|7   6|  _ _ _ _ _|7
  2| |_|1   2| |_|  1   2| |_|    1   2| |_|      1   2|_|_|        1
  1| |      1| |        1| |          1|_|
  1| |      1| |        1|_|
  1| |      1|_|
  1|_|
.
    _ _       _ _ _       _ _ _       _ _ _ _       _ _ _ _       _ _ _ _ _
  2|  _|6   3|  _ _|6   3|  _ _|6   4|  _ _ _|6   4|  _ _ _|6   5|  _ _ _ _|6
  2| | |2   2| | |  2   3| |_ _|2   2| | |    2   3| |_ _|  2   3|_|_ _|    2
  2| |_|    2| |_|      1| |        2|_|_|        1|_|
  1| |      1|_|        1|_|
  1|_|
.
    _ _       _ _ _        _ _ _ _
  2|  _|5   3|  _ _|5    4|  _ _ _|5
  2| | |3   3| |  _|3    4|_|_ _ _|3
  2| | |    2|_|_|
  2|_|_|
.
There are  5 right angles of size 1, so T(8,1) = 5*1 = 5.
There are  6 right angles of size 2, so T(8,2) = 6*2 = 12.
There are  3 right angles of size 3, so T(8,3) = 3*3 = 9.
There are no right angle  of size 4, so T(8,4) = 0*4 = 0.
There are  3 right angles of size 5, so T(8,5) = 3*5 = 15.
There are  6 right angles of size 6, so T(8,6) = 6*6 = 36.
There are  5 right angles of size 7, so T(8,7) = 5*7 = 35.
There are  8 right angles of size 8, so T(8,8) = 8*8 = 64.
Hence the 8th row of triangle is [5, 12, 9, 0, 15, 36, 35, 64].
The row sum gives A066186(8) = 8*A000041(8) = 8*22 = 176.

G. E. Andrews, Theory of Partitions, Cambridge University Press, 1984, page 143.

Row sums give A066186, n >= 1.
Row sums of the terms that are after last zero give A179862.
Cf. A188674.
Cf. A000041, A000290, A330369, A330375, A330378.

T(n,k) = k*A330369(n,k).

A179864 The unrestricted partition statistic defined by A049085(n,k)+A036043(n,k)- 1.

Original entry on oeis.org

1, 2, 2, 3, 3, 3, 4, 4, 3, 4, 4, 5, 5, 4, 5, 4, 5, 5, 6, 6, 5, 4, 6, 5, 4, 6, 5, 6, 6, 7, 7, 6, 5, 7, 6, 5, 5, 7, 6, 5, 7, 6, 7, 7, 8, 8, 7, 6, 5, 8, 7, 6, 6, 5, 8, 7, 6, 6, 5, 8, 7, 6, 8, 7, 8, 8, 9, 9, 8, 7, 6, 9, 8, 7, 6, 7, 6, 5, 9, 8, 7, 7, 6, 6, 9, 8, 7, 7, 6, 9, 8, 7, 9, 8, 9, 9, 10, 10, 9, 8, 7, 6, 10, 9, 8

Offset: 1

Alford Arnold, Aug 02 2010

			1;
2,2;
3,3,3;
4,4,3,4,4;
5,5,4,5,4,5,5;
6,6,5,4,6,5,4,6,5,6,6;
7,7,6,5,7,6,5,5,7,6,5,7,6,7,7;

Cf. A000041 (row lengths), A179862 (row sums), A105805 (the rank statistic)

A366175 The number of lit cells in weakly decreasing partitions of n when light shines from the north west and only the first column is lit. Here partitions are represented from left to right by columns of cells.

Original entry on oeis.org

1, 2, 5, 7, 15, 22, 35, 54, 86, 115, 175, 248, 351, 480, 662, 890, 1229, 1622, 2154, 2820, 3718, 4814, 6269, 8048, 10303, 13086, 16648, 20998, 26540, 33196, 41509, 51607, 64086, 79162, 97769, 120213, 147587, 180401, 220173, 267697, 325211, 393778, 476237

Offset: 1

Arnold Knopfmacher, Oct 03 2023

nonn

A. Blecher, A. Knopfmacher, and M. E. Mays, Casting light on integer partitions, preprint.

Cf. A366069, A179862, A366157.

T[r_, s_] := If[s > r, 0, If[s == 0, 1, If[r == 1 && s == 1, q, If[r == 2 && s == 1, q*(1 + q), q^s*Sum[T[r - 1, i], {i, 0, s}]]]]]; nmax = 15; Rest[CoefficientList[Series[Sum[(r + 1)*q^(r + 1)*Sum[T[r, s], {s, 0, r}], {r, 0, nmax}], {q, 0, nmax}], q]] (* Vaclav Kotesovec, Oct 04 2023 *)

G.f.: Sum_{r>=0} (r+1)*q^(r+1)*T_q(r) where T_q(k) = Sum_{s=0..k} t(k,s) with t(r,s) = q^s*Sum_{i=0..s} t(r-1,i) and initial conditions t(1,1) = q; t(2,1) = q(1+q); t(r,0) = 1; t(r,s) = 0 for s>r.

a(14)-a(16) from Vaclav Kotesovec, Oct 04 2023

a(17)-a(43) from Alois P. Heinz, Oct 04 2023

cp's OEIS Frontend

A220517 First differences of A225600. Also A141285 and A194446 interleaved.

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A330375 Irregular triangle read by rows: T(n,k) (n>=1) is the sum of the lengths of all k-th right angles in all partitions of n.

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A330379 Triangle read by rows: T(n,k) (1 <= k <= n) is the sum of the sizes of all right angles of size k of all partitions of n.

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A179864 The unrestricted partition statistic defined by A049085(n,k)+A036043(n,k)- 1.

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A366175 The number of lit cells in weakly decreasing partitions of n when light shines from the north west and only the first column is lit. Here partitions are represented from left to right by columns of cells.

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