A141285
Largest part of the n-th partition of j in the list of colexicographically ordered partitions of j, if 1 <= n <= A000041(j).
Original entry on oeis.org
1, 2, 3, 2, 4, 3, 5, 2, 4, 3, 6, 3, 5, 4, 7, 2, 4, 3, 6, 5, 4, 8, 3, 5, 4, 7, 3, 6, 5, 9, 2, 4, 3, 6, 5, 4, 8, 4, 7, 6, 5, 10, 3, 5, 4, 7, 3, 6, 5, 9, 5, 4, 8, 7, 6, 11, 2, 4, 3, 6, 5, 4, 8, 4, 7, 6, 5, 10, 3, 6, 5, 9, 4, 8, 7, 6, 12
Offset: 1
Written as a triangle T(j,k) the sequence begins:
1;
2;
3;
2, 4;
3, 5;
2, 4, 3, 6;
3, 5, 4, 7;
2, 4, 3, 6, 5, 4, 8;
3, 5, 4, 7, 3, 6, 5, 9;
2, 4, 3, 6, 5, 4, 8, 4, 7, 6, 5, 10;
3, 5, 4, 7, 3, 6, 5, 9, 5, 4, 8, 7, 6, 11;
...
------------------------------------------
n A000041 a(n)
------------------------------------------
1 = p(1) 1
2 = p(2) 2 .
3 = p(3) . 3
4 2 .
5 = p(4) 4 .
6 . 3
7 = p(5) . 5
8 2 .
9 4 .
10 3 .
11 = p(6) 6 .
12 . 3
13 . 5
14 . 4
15 = p(7) . 7
...
From _Omar E. Pol_, Aug 22 2013: (Start)
Illustration of initial terms (n = 1..11) in three ways: as the largest parts of the partitions of 6 (see A026792), also as the largest parts of the regions of the diagram, also as the diagonal of triangle. By definition of "region" the largest part of the n-th region is also the largest part of the n-th partition (see below):
--------------------------------------------------------
. Diagram Triangle in which
Partitions of regions rows are partitions
of 6 and partitions and columns are regions
--------------------------------------------------------
. _ _ _ _ _ _
6 _ _ _ | 6
3+3 _ _ _|_ | 3 3
4+2 _ _ | | 4 2
2+2+2 _ _|_ _|_ | 2 2 2
5+1 _ _ _ | | 5 1
3+2+1 _ _ _|_ | | 3 1 1
4+1+1 _ _ | | | 4 1 1
2+2+1+1 _ _|_ | | | 2 2 1 1
3+1+1+1 _ _ | | | | 3 1 1 1
2+1+1+1+1 _ | | | | | 2 1 1 1 1
1+1+1+1+1+1 | | | | | | 1 1 1 1 1 1
...
The equivalent sequence for compositions is A001511. Explanation: for the positive integer j the diagram of regions of the set of compositions of j has 2^(j-1) regions. The largest part of the n-th region is A001511(n). The number of parts is A006519(n). On the other hand the diagram of regions of the set of partitions of j has A000041(j) regions. The largest part of the n-th region is a(n) = A001511(A228354(n)). The number of parts is A194446(n). Both diagrams have j sections. The diagram for partitions can be interpreted as one of the three views of a three dimensional diagram of compositions in which the rows of partitions are in orthogonal direction to the rest. For the first five sections of the diagrams see below:
--------------------------------------------------------
. Diagram Diagram
. of regions of regions
. and compositions and partitions
---------------------------------------------------------
. j = 1 2 3 4 5 j = 1 2 3 4 5
---------------------------------------------------------
n A001511 A228354 a(n)
---------------------------------------------------------
1 1 _| | | | | ............ 1 1 _| | | | |
2 2 _ _| | | | ............ 2 2 _ _| | | |
3 1 _| | | | ......... 4 3 _ _ _| | |
4 3 _ _ _| | | ../ ....... 6 2 _ _| | |
5 1 _| | | | / ....... 8 4 _ _ _ _| |
6 2 _ _| | | ../ / .... 12 3 _ _ _| |
7 1 _| | | / / . 16 5 _ _ _ _ _|
8 4 _ _ _ _| | ../ / /
9 1 _| | | | / /
10 2 _ _| | | / /
11 1 _| | | / /
12 3 _ _ _| | ../ /
13 1 _| | | /
14 2 _ _| | /
15 1 _| | /
16 5 _ _ _ _ _| ../
...
Also we can draw an infinite Dyck path in which the n-th odd-indexed line segment has a(n) up-steps and the n-th even-indexed line segment has A194446(n) down-steps. Note that the height of the n-th largest peak between two successive valleys at height 0 is also the partition number A000041(n). See below:
. 5
. /\ 3
. 4 / \ 4 /\
. /\ / \ /\ /
. 3 / \ 3 / \ / \/
. 2 /\ 2 / \ /\/ \ 2 /
. 1 /\ / \ /\/ \ / \ /\/
. /\/ \/ \/ \/ \/
.
.(End)
Cf.
A000041,
A135010,
A182730,
A182731,
A182732,
A182733,
A182982,
A182983,
A182703,
A193870,
A194446,
A194447,
A194550,
A206437,
A210979,
A210980,
A211978,
A220517,
A225600,
A225610.
-
Last/@DeleteCases[DeleteCases[Sort@PadRight[Reverse/@IntegerPartitions[13]], x_ /; x == 0, 2], {}] (* updated _Robert Price, May 15 2020 *)
Better definition and edited by
Omar E. Pol, Oct 17 2013
A207380
Total area of the shadows of the three views of a three-dimensional version of the shell model of partitions with n shells.
Original entry on oeis.org
0, 3, 10, 21, 42, 70, 122, 187, 298, 443, 667, 957, 1401, 1960, 2775, 3828, 5295, 7167, 9745, 12998, 17380, 22915, 30196, 39347, 51274, 66126, 85209, 108942, 139055, 176273, 223148, 280733, 352623, 440646, 549597, 682411, 845852, 1044084, 1286512, 1579582
Offset: 0
For n = 5 the three views of the three-dimensional shell model of partitions with 5 shells look like this:
.
. A066186(5) = 35 A006128(5) = 20
.
. 1 1 1 1 1 5
. 1 1 1 1 1 3 2
. 1 1 1 1 1 4 1
. 1 1 1 1 1 2 2 1
. 1 1 1 1 1 3 1 1
. 1 1 1 1 1 2 1 1 1
. 1 1 1 1 1 1 1 1 1 1
.
.
. 7 6 4 2 1
. 1 2 3 2
. 1 1 2
. 1 1
. 1
.
. A000217(5) = 15
.
The areas of the shadows of the three views are A066186(5) = 35, A006128(5) = 20 and A000217(5) = 15, therefore the total area of the three shadows is 35+20+15 = 70, so a(5) = 70.
Cf.
A000041,
A000217,
A006128,
A026792,
A066186,
A135010,
A138121,
A141285,
A182703,
A182715,
A206437,
A209655.
-
b:= proc(n, i) option remember; local f, g;
if n=0 or i=1 then [1, n]
else f:= b(n, i-1); g:= `if`(i>n, [0, 0], b(n-i, i));
[f[1]+g[1], f[2]+g[2]+g[1]]
fi
end:
a:= n-> n*b(n, n)[1] +b(n, n)[2] +n*(n+1)/2:
seq (a(n), n=0..50); # Alois P. Heinz, Mar 22 2012
-
b[n_, i_] := b[n, i] = Module[{f, g}, If [n == 0 || i == 1, {1, n}, f = b[n, i-1]; g = If[i>n, {0, 0}, b[n-i, i]]; Join[f[[1]] + g[[1]], f[[2]] + g[[2]] + g[[1]] ]]]; a[n_] := n*b[n, n][[1]] + b[n, n][[2]] + n*(n+1)/2; Table[a[n], {n, 0, 50}] (* Jean-François Alcover, Jun 18 2015, after Alois P. Heinz *)
A210970
Total area of the shadows of the three views of a three-dimensional version of the shell model of partitions with n shells.
Original entry on oeis.org
0, 3, 9, 18, 34, 55, 91, 136, 208, 301, 439, 616, 876, 1203, 1665, 2256, 3062, 4083, 5459, 7186, 9470, 12335, 16051, 20688, 26648, 34027, 43395, 54966, 69496, 87341, 109591, 136766, 170382, 211293, 261519, 322382, 396694, 486327, 595143, 725954, 883912
Offset: 0
For n = 6 the illustration of the three views of a three-dimensional version of the shell model of partitions with 6 shells looks like this:
.
. A006128(6) = 35 A006128(6) = 35
.
. 6 6
. 3 3 3 3
. 4 2 4 2
. 2 2 2 2 2 2
. 5 1 5 1
. 3 2 1 3 2 1
. 4 1 1 4 1 1
. 2 2 1 1 2 2 1 1
. 3 1 1 1 3 1 1 1
. 2 1 1 1 1 2 1 1 1 1
. 1 1 1 1 1 1 1 1 1 1 1 1
.
.
. 1 2 5 9 12 6 \
. 1 1 3 5 6 \
. 1 1 2 4 \ 6th slice of
. 1 1 2 / tetrahedron A210961
. 1 1 /
. 1 /
.
. A000217(6) = 21
.
The areas of the shadows of the three views are A006128(6) = 35, A006128(6) = 35 and A000217(6) = 21, therefore the total area of the three shadows is 35+35+21 = 91, so a(6) = 91.
A210990
Total area of the shadows of the three views of the shell model of partitions with n regions.
Original entry on oeis.org
0, 3, 10, 21, 26, 44, 51, 75, 80, 92, 99, 136, 143, 157, 166, 213, 218, 230, 237, 260, 271, 280, 348, 355, 369, 378, 403, 410, 427, 438, 526, 531, 543, 550, 573, 584, 593, 631, 640, 659, 672, 683, 804, 811, 825, 834, 859, 866, 883, 894, 938, 949, 958
Offset: 0
For n = 11 the three views of the shell model of partitions with 11 regions look like this:
.
. A182181(11) = 35 A182244(11) = 66
.
. 6 * * * * * 6
. 3 3 P * * 3 * * 3
. 2 4 a * * * 4 * 2
. 2 2 2 r * 2 * 2 * 2
. 1 5 t * * * * 5 1
. 1 2 3 i * * 3 * 2 1
. 1 1 4 t * * * 4 1 1
. 1 1 2 2 i * 2 * 2 1 1
. 1 1 1 3 o * * 3 1 1 1
. 1 1 1 1 2 n * 2 1 1 1 1
. 1 1 1 1 1 1 s 1 1 1 1 1 1
. <------- Regions ------ ------------> N
. L
. a 1
. r * 2
. g * * 3
. e * 2
. s * * * 4
. t * * 3
. * * * * 5
. p * 2
. a * * * 4
. r * * 3
. t * * * * * 6
. s
. A182727(11) = 35
.
The areas of the shadows of the three views are A182244(11) = 66, A182181(11) = 35 and A182727(11) = 35, therefore the total area of the three shadows is 66+35+35 = 136, so a(11) = 136.
A210980
Total area of the shadows of the three views of the shell model of partitions, version "Tree", with n shells.
Original entry on oeis.org
0, 3, 10, 21, 42, 69, 123, 189, 304, 458, 693, 998, 1474, 2067, 2927, 4056, 5613, 7595, 10335, 13782, 18411, 24276, 31944, 41583, 54152, 69762, 89758, 114668, 146181, 185083, 234051, 294126, 368992, 460669, 573906, 711865, 881506, 1087023, 1338043
Offset: 0
For n = 7 the shadows of the three views of the shell model of partitions version "tree" with seven shells looks like this:
. | Partitions
. A194805(7) = 25 A066186(7) = 105 | of 7
. |
. 1 * * * * * * 1 | 7
. 2 * * * 1 * * 2 | 4+3
. 2 * * * * 1 * 2 | 5+2
. 3 * * 1 * 2 * 3 | 3+2+2
. 1 2 * * * * * 1 2 | 6+1
. 2 3 * * 1 * * 2 3 | 3+3+1
. 2 3 * * * 1 * 2 3 | 4+2+1
. 3 4 * 1 * 2 * 3 4 | 2+2+2+1
. 3 1 * * * * 1 2 3 | 5+1+1
. 4 2 * * 1 * 2 3 4 | 3+2+1+1
. 1 4 * * * 1 2 3 4 | 4+1+1+1
. 2 5 * 1 * 2 3 4 5 | 2+2+1+1+1
. 5 1 * * 1 2 3 4 5 | 3+1+1+1+1
. 1 6 * 1 2 3 4 5 6 | 2+1+1+1+1+1
. 7 1 2 3 4 5 6 7 | 1+1+1+1+1+1+1
. ---------------------------------- |
. |
. * * * * 1 * * * * |
. * * * 1 2 * * * * |
. * 1 * * 2 1 * * * |
. * * 1 2 2 * * 1 * |
. * * * * 2 2 1 * * |
. 1 2 2 3 2 * * * * |
. 2 3 2 2 1 |
. |
. A194804(7) = 59 |
.
Note that, as a variant, in this case each part is labeled with its position in the partition.
The areas of the shadows of the three views are A066186(7) = 105, A194804(7) = 59 and A194805(7) = 25, therefore the total area of the three shadows is 105+59+25 = 189, so a(7) = 189.
A210991
Total area of the shadows of the three views of the shell model of partitions with n regions.
Original entry on oeis.org
0, 3, 9, 18, 21, 35, 39, 58, 61, 67, 71, 99, 103, 110, 115, 152, 155, 161, 165, 175, 181, 186, 238, 242, 249, 254, 265, 269, 277, 283, 352, 355, 361, 365, 375, 381, 386, 401, 406, 415, 422, 428, 522, 526, 533, 538, 549, 553, 561, 567, 584, 590, 595, 606
Offset: 0
For n = 11 the three views of the shell model of partitions with 11 regions look like this:
.
. A182181(11) = 35 A210692(11) = 29
.
. 1 1
. 1 1
. 1 1
. 1 1
. 1 1 1 1
. 1 1 1 1
. 1 1 1 1 1 1
. 2 1 1 1 1 2
. 2 1 1 1 1 1 1 2
. 3 2 2 2 1 1 1 1 2 2 3
. 6 3 4 2 5 3 4 2 3 2 1 1 2 3 4 5 6
. <------- Regions ------ ------------> N
. L
. a 1
. r * 2
. g * * 3
. e * 2
. s * * * 4
. t * * 3
. * * * * 5
. p * 2
. a * * * 4
. r * * 3
. t * * * * * 6
. s
.
. A182727(11) = 35
.
The areas of the shadows of the three views are A182181(11) = 35, A182727(11) = 35 and A210692(11) = 29, therefore the total area of the three shadows is 35+35+29 = 99, so a(11) = 99.
Since n = 11 is a partition number A000041 we can see that the rotated structure with 11 regions shows each row as a partition of 6 because A000041(6) = 11. See below:
.
. 6
. 3 3
. 4 2
. 2 2 2
. 5 1
. 3 2 1
. 4 1 1
. 2 2 1 1
. 3 1 1 1
. 2 1 1 1 1
. 1 1 1 1 1 1
.
Cf.
A000041,
A026905,
A135010,
A138121,
A141285,
A182703,
A194446,
A182181,
A182727,
A186114,
A206437,
A210692.
A194803
Number of parts that are visible in one of the three views of the shell model of partitions version "Tree" with n shells.
Original entry on oeis.org
0, 1, 3, 5, 8, 11, 17, 23, 33, 46, 64, 86, 121, 161, 217, 291, 388, 507, 671, 870, 1131, 1458, 1872, 2383, 3042, 3840, 4841, 6076, 7605, 9460, 11765, 14544, 17950, 22073, 27077, 33092, 40395, 49113, 59611, 72162, 87185, 105035, 126366
Offset: 0
Illustration of one of the three views with seven shells:
1) Small version:
.
Level
1 A182732 <- 6 3 4 2 1 3 5 4 7 -> A182733
2 3 2 2 1 2 2 3
3 2 1 2
4 1
5 Table 2.0 1 Table 2.1
6 1
7 1
.
. A182742 A182982 A182743 A182983
. A182992 A182994 A182993 A182995
.
2) Large version:
.
. . . . . 1 . . . .
. . . . 1 2 . . . .
. . 1 . . 2 1 . . .
. . . 1 2 2 . . 1 .
. . . . . 2 2 1 . .
. 1 2 2 3 2 . . . .
. 2 3 2 2 1
.
The large version shows the parts labeled with the level of the part where "the level of a part" is its position in the partition. In both versions there are 23 parts that are visible, so a(7) = 23. Also using the formula we have a(7) = 7+8+8 = 23.
Cf.
A006128,
A096541,
A138135,
A135010,
A138121,
A141285,
A182732,
A182733,
A182742,
A182743,
A182982,
A182983,
A182992-
A182995,
A194804,
A194805,
A210979.
Showing 1-7 of 7 results.
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