Original entry on oeis.org
0, 1, 3, 5, 8, 11, 15, 18, 22, 26, 31, 35, 40, 45, 51, 55, 60, 65, 71, 77, 83, 90, 95, 101, 107, 114, 120, 127, 134, 142, 147, 153, 159, 166, 173, 180, 188, 195, 203, 211, 219, 228, 234, 241, 248, 256, 263, 271, 279, 288, 296, 304, 313, 322, 331, 341
Offset: 1
Written as a triangle:
0;
1;
3;
5,8;
11,15;
18,22,26,31;
35,40,45,51;
55,60,65,71,77,83,90;
95,101,107,114,120,127,134,142;
147,153,159,166,173,180,188,195,203,211,219,228;
234,241,248,256,263,271,279,288,296,304,313,322,331,341;
A196087
Sum of all parts minus the total numbers of parts of all partitions of n.
Original entry on oeis.org
0, 1, 3, 8, 15, 31, 51, 90, 142, 228, 341, 525, 757, 1110, 1572, 2233, 3084, 4286, 5812, 7910, 10580, 14145, 18659, 24626, 32099, 41814, 53976, 69559, 88932, 113557, 143967, 182241, 229353, 288078, 360029, 449158, 557757, 691369, 853628, 1051974
Offset: 1
For n = 4 the five partitions of 4 are: 4, 3+1, 2+2, 2+1+1, 1+1+1+1. The sum of all parts is 4+3+1+2+2+2+1+1+1+1+1+1 = 20. The sum of all parts is also the product n*p(n) = 4*5 = 20, where p(n) = A000041(n) is the number of partitions of n. On the other hand the number of parts in all partitions of 4 is equal to 12, so a(4) = 20-12 = 8.
-
b:= proc(n, i) option remember; local f, g;
if n=0 then [1, 0]
elif i<1 then [0, 0]
elif i>n then b(n, i-1)
else f:= b(n, i-1); g:= b(n-i, i);
[f[1]+g[1], f[2]+g[2] +g[1]*(i-1)]
fi
end:
a:= n-> b(n, n)[2]:
seq(a(n), n=1..50); # Alois P. Heinz, Feb 20 2012
-
b[n_, i_] := b[n, i] = Module[{f, g}, Which[n==0, {1, 0}, i<1, {0, 0}, i>n, b[n, i-1], True, f = b[n, i-1]; g = b[n-i, i]; {f[[1]] + g[[1]], f[[2]] + g[[2]] + g[[1]]*(i-1)}]]; a[n_] := b[n, n][[2]]; Table[a[n], {n, 1, 50}] (* Jean-François Alcover, Oct 22 2015, after Alois P. Heinz *)
-
a(n) = n*numbpart(n) - sum(m=1, n, numdiv(m)*numbpart(n-m)); \\ Michel Marcus, Oct 22 2015
A228354
Indices (k) of partitions in the list of compositions of j in colexicographic order, if 1<=k<=2^(j-1), j>=1.
Original entry on oeis.org
1, 2, 4, 6, 8, 12, 16, 22, 24, 28, 32, 44, 48, 56, 64, 86, 88, 92, 96, 112, 120, 128, 172, 176, 184, 192, 220, 224, 240, 256, 342, 344, 348, 352, 368, 376, 384, 440, 448, 480, 496, 512, 684, 688, 696, 704, 732, 736, 752, 768, 880, 888, 896, 960, 992, 1024
Offset: 1
For j = 5 consider the list of compositions of 5 in colexicographic order (see A228525). The indices of the partitions are 1, 2, 4, 6, 8, 12, 16 which are the first A000041(5) terms of this sequence, see below:
---------------------------------------------------------
. Compositions Partitions
k of 5 of 5 n a(n)
---------------------------------------------------------
1 1+1+1+1+1 * ............... * 1+1+1+1+1 1 1
2 2+1+1+1 * ............... * 2+1+1+1 2 2
3 1+2+1+1 ........... * 3+1+1 3 4
4 3+1+1 * .../ .......... * 2+2+1 4 6
5 1+1+2+1 / ......... * 4+1 5 8
6 2+2+1 * .../ / ...... * 3+2 6 12
7 1+3+1 / / ... * 5 7 16
8 4+1 * .../ / /
9 1+1+1+2 / /
10 2+1+2 / /
11 1+2+2 / /
12 3+2 * .../ /
13 1+1+3 /
14 2+3 /
15 1+4 /
16 5 * .../
.
Written as an irregular triangle the sequence begins:
1;
2;
4;
6,8;
12,16;
22,24,28,32;
44,48,56,64;
86,88,92,96,112,120,128;
172,176,184,192,220,224,240,256;
342,344,348,352,368,376,384,440,448,480,496,512;
684,688,696,704,732,736,752,768,880,888,896,960,992,1024;
...
A207035
Sum of all parts minus the total number of parts of the last section of the set of partitions of n.
Original entry on oeis.org
0, 1, 2, 5, 7, 16, 20, 39, 52, 86, 113, 184, 232, 353, 462, 661, 851, 1202, 1526, 2098, 2670, 3565, 4514, 5967, 7473, 9715, 12162, 15583, 19373, 24625, 30410, 38274, 47112, 58725, 71951, 89129, 108599, 133612, 162259, 198346, 239825, 291718, 351269, 425102
Offset: 1
For n = 7 the last section of the set of partitions of 7 looks like this:
.
. (. . . . . . 7)
. (. . . 4 . . 3)
. (. . . . 5 . 2)
. (. . 3 . 2 . 2)
. (1)
. (1)
. (1)
. (1)
. (1)
. (1)
. (1)
. (1)
. (1)
. (1)
. (1)
.
The sum of all parts = 7+4+3+5+2+3+2+2+1*11 = 39, on the other hand the total number of parts is 1+2+2+3+1*11 = 19, so a(7) = 39 - 19 = 20. Note that the number of dots in the picture is also equal to a(7) = 6+5+5+4 = 20.
Cf.
A006128,
A066186,
A135010,
A138121,
A138135,
A138137,
A138879,
A138880,
A187219,
A194548,
A207038.
-
b:= proc(n, i) option remember; local f, g;
if n=0 then [1, 0]
elif i<2 then [0, 0]
elif i>n then b(n, i-1)
else f:= b(n, i-1); g:= b(n-i, i);
[f[1]+g[1], f[2]+g[2] +g[1]*(i-1)]
fi
end:
a:= n-> b(n, n)[2]:
seq (a(n), n=1..50); # Alois P. Heinz, Feb 20 2012
-
b[n_, i_] := b[n, i] = Module[{f, g}, Which[n==0, {1, 0}, i<2, {0, 0}, i>n , b[n, i-1], True, f = b[n, i-1]; g = b[n-i, i]; {f[[1]] + g[[1]], f[[2]] + g[[2]] + g[[1]]*(i-1)}]]; a[n_] := b[n, n][[2]]; Table[a[n], {n, 1, 50}] (* Jean-François Alcover, Sep 13 2015, after Alois P. Heinz *)
A230440
Triangle read by rows in which row n lists A000041(n-1) 1's followed by the list of partitions of n that do not contain 1 as a part in colexicographic order.
Original entry on oeis.org
1, 1, 2, 1, 1, 3, 1, 1, 1, 2, 2, 4, 1, 1, 1, 1, 1, 3, 2, 5, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 4, 2, 3, 3, 6, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 2, 2, 5, 2, 4, 3, 7, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 4, 2, 2, 3, 3, 2, 6, 2, 5, 3, 4, 4, 8
Offset: 1
Illustration of initial terms (row = 1..6). The table shows the six sections of the set of partitions of 6 in three ways. Note that before the dissection, the set of partitions was in colexicographic order, see A211992. More generally, in a master model, the six sections of the set of partitions of 6 also can be interpreted as the first six sections of the set of partitions of any integer >= 6.
---------------------------------------------------------
n j Diagram Parts Parts
---------------------------------------------------------
. _
1 1 |_| 1; 1;
. _
2 1 _| | 1, 1,
2 2 |_ _| 2; 2;
. _
3 1 | | 1, 1,
3 2 _ _| | 1, 1,
3 3 |_ _ _| 3; 3;
. _
4 1 | | 1, 1,
4 2 | | 1, 1,
4 3 _ _ _| | 1, 1,
4 4 |_ _| | 2,2, 2,2,
4 5 |_ _ _ _| 4; 4;
. _
5 1 | | 1, 1,
5 2 | | 1, 1,
5 3 | | 1, 1,
5 4 | | 1, 1,
5 5 _ _ _ _| | 1, 1,
5 6 |_ _ _| | 3,2, 3,2,
5 7 |_ _ _ _ _| 5; 5;
. _
6 1 | | 1, 1,
6 2 | | 1, 1,
6 3 | | 1, 1,
6 4 | | 1, 1,
6 5 | | 1, 1,
6 6 | | 1, 1,
6 7 _ _ _ _ _| | 1, 1,
6 8 |_ _| | | 2,2,2, 2,2,2,
6 9 |_ _ _ _| | 4,2, 4,2,
6 10 |_ _ _| | 3,3, 3,3,
6 11 |_ _ _ _ _ _| 6; 6;
...
Triangle begins:
[1];
[1],[2];
[1],[1],[3];
[1],[1],[1],[2,2],[4];
[1],[1],[1],[1],[1],[3,2],[5];
[1],[1],[1],[1],[1],[1],[1],[2,2,2],[4,2],[3,3],[6];
...
Cf.
A000041,
A135010,
A138121,
A141285,
A182703,
A187219,
A193870,
A194446,
A206437,
A207031,
A207034,
A207383,
A207379,
A211009.
A210946
Triangle read by rows: T(n,k) = sum of parts in the k-th column of the mirror of the last section of the set of partitions of n with its parts aligned to the right margin.
Original entry on oeis.org
1, 3, 5, 9, 2, 12, 3, 20, 9, 2, 25, 11, 3, 38, 22, 9, 2, 49, 28, 14, 3, 69, 44, 26, 9, 2, 87, 55, 37, 14, 3, 123, 83, 62, 29, 9, 2, 152
Offset: 1
For n = 7 the illustration shows two arrangements of the last section of the set of partitions of 7:
.
. (7) (7)
. (4+3) (3+4)
. (5+2) (2+5)
. (3+2+2) (2+2+3)
. (1) (1)
. (1) (1)
. (1) (1)
. (1) (1)
. (1) (1)
. (1) (1)
. (1) (1)
. (1) (1)
. (1) (1)
. (1) (1)
. (1) (1)
. ---------
. 25,11,3
.
The left hand picture shows the last section of 7 with its parts aligned to the right margin. In the right hand picture (the mirror) we can see that the sum of all parts of the columns 1..3 are 25, 11, 3 therefore row 7 lists 25, 11, 3.
Written as a triangle begins:
1;
3;
5;
9, 2;
12, 3;
20, 9, 2;
25, 11, 3;
38, 22, 9, 2;
49, 28, 14, 3;
69, 44, 26, 9, 2;
87, 55, 37, 14, 3,
123, 83, 62, 29, 9, 2;
Cf.
A135010,
A138121,
A182703,
A194714,
A196807,
A206437,
A207031,
A207034,
A207035,
A210945,
A210952,
A210953.
Showing 1-6 of 6 results.
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