A341062
Sequence whose partial sums give A000005.
Original entry on oeis.org
1, 1, 0, 1, -1, 2, -2, 2, -1, 1, -2, 4, -4, 2, 0, 1, -3, 4, -4, 4, -2, 0, -2, 6, -5, 1, 0, 2, -4, 6, -6, 4, -2, 0, 0, 5, -7, 2, 0, 4, -6, 6, -6, 4, 0, -2, -2, 8, -7, 3, -2, 2, -4, 6, -4, 4, -4, 0, -2, 10, -10, 2, 2, 1, -3, 4, -6, 4, -2, 4, -6, 10, -10, 2, 2, 0, -2, 4, -6, 8, -5, -1, -2, 10, -8, 0, 0, 4, -6, 10
Offset: 1
Cf.
A000027,
A000041,
A000070,
A000217,
A006128,
A006218,
A014153,
A036469,
A055507,
A078567,
A138137,
A284870,
A305082,
A340793.
-
Join[{1}, Differences[Table[DivisorSigma[0, n], {n, 1, 90}]]] (* Amiram Eldar, Feb 06 2021 *)
A299779
Triangle read by rows: T(n,k) is the total number of cliques of size k in all partitions of all positive integers <= n.
Original entry on oeis.org
1, 2, 1, 5, 1, 1, 9, 3, 1, 1, 17, 5, 2, 1, 1, 28, 9, 4, 2, 1, 1, 47, 14, 7, 3, 2, 1, 1, 73, 24, 10, 6, 3, 2, 1, 1, 114, 35, 17, 9, 5, 3, 2, 1, 1, 170, 55, 25, 14, 8, 5, 3, 2, 1, 1, 253, 80, 38, 20, 13, 7, 5, 3, 2, 1, 1, 365, 118, 55, 31, 18, 12, 7, 5, 3, 2, 1, 1, 525, 167, 80, 44, 27, 17, 11, 7, 5, 3, 2, 1, 1
Offset: 1
Triangle begins:
1;
2, 1;
5, 1, 1;
9, 3, 1, 1;
17, 5, 2, 1, 1;
28, 9, 4, 2, 1, 1;
47, 14, 7, 3, 2, 1, 1;
73, 24, 10, 6, 3, 2, 1, 1;
114, 35, 17, 9, 5, 3, 2, 1, 1;
170, 55, 25, 14, 8, 5, 3, 2, 1, 1;
253, 80, 38, 20, 13, 7, 5, 3, 2, 1, 1;
365, 118, 55, 31, 18, 12, 7, 5, 3, 2, 1, 1;
525, 167, 80, 44, 27, 17, 11, 7, 5, 3, 2, 1, 1;
...
-
b:= proc(n, p, k) option remember; `if`(n=0, [1, 0], `if`(p<1, [0, 0],
add((l->`if`(m=k, l+[0, l[1]], l))(b(n-p*m, p-1, k)), m=0..n/p)))
end:
T:= proc(n, k) option remember;
b(n$2, k)[2]+`if`(nAlois P. Heinz, Apr 27 2018
-
b[n_, p_, k_] := b[n, p, k] = If[n == 0, {1, 0}, If[p < 1, {0, 0}, Sum[ Function[l, If[m==k, l+{0, l[[1]]}, l]][b[n-p*m, p-1, k]], {m, 0, n/p}]]];
T[n_, k_] := b[n, n, k][[2]] + If[n < k, 0, T[n-1, k]];
Table[Table[T[n, k], {k, 1, n}], {n, 1, 20}] // Flatten (* Jean-François Alcover, Dec 07 2019, after Alois P. Heinz *)
A340526
Triangle read by rows: T(n,k) = A006218(n-k+1)*A000041(k-1), 1 <= k <= n.
Original entry on oeis.org
1, 3, 1, 5, 3, 2, 8, 5, 6, 3, 10, 8, 10, 9, 5, 14, 10, 16, 15, 15, 7, 16, 14, 20, 24, 25, 21, 11, 20, 16, 28, 30, 40, 35, 33, 15, 23, 20, 32, 42, 50, 56, 55, 45, 22, 27, 23, 40, 48, 70, 70, 88, 75, 66, 30, 29, 27, 46, 60, 80, 98, 110, 120, 110, 90, 42, 35, 29, 54, 69, 100, 112, 154, 150, 176, 150, 126, 56
Offset: 1
Triangle begins:
1;
3, 1;
5, 3, 2;
8, 5, 6, 3;
10, 8, 10, 9, 5;
14, 10, 16, 15, 15, 7;
16, 14, 20, 24, 25, 21, 11;
20, 16, 28, 30, 40, 35, 33, 15;
23, 20, 32, 42, 50, 56, 55, 45, 22;
27, 23, 40, 48, 70, 70, 88, 75, 66, 30;
29, 27, 46, 60, 80, 98, 110, 120, 110, 90, 42;
35, 29, 54, 69, 100, 112, 154, 150, 176, 150, 126, 56;
...
For n = 6 the calculation of every term of row 6 is as follows:
--------------------------
k A000041 T(6,k)
1 1 * 14 = 14
2 1 * 10 = 10
3 2 * 8 = 16
4 3 * 5 = 15
5 5 * 3 = 15
6 7 * 1 = 7
. A006218
--------------------------
The sum of row 6 is 14 + 10 + 16 + 15 + 15 + 7 = 77, equaling A284870(6).
A340581
Irregular triangle read by rows in which row n has length A014153(n-1) and every column k lists the positive integers A000027, n >= 1, k >= 1.
Original entry on oeis.org
1, 2, 1, 1, 3, 2, 2, 1, 1, 1, 1, 4, 3, 3, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 5, 4, 4, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 6, 5, 5, 4, 4, 4, 4, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
Offset: 1
Triangle begins:
1;
2, 1, 1;
3, 2, 2, 1, 1, 1, 1;
4, 3, 3, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1;
5, 4, 4, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1;
...
For n = 4, by definition the length of row 6 is A014153(4-1) = A014153(3) = 14, so the row 4 of triangle has 14 terms. Since every column lists the positive integers A000027 so the row 4 is [4, 3, 3, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1].
Then we have that the divisors of the numbers of the 4th row are:
.
4th row of the triangle ----------> 4 3 3 2 2 2 2 1 1 1 1 1 1 1
2 1 1 1 1 1 1
1
.
There are fourteen 1's, five 2's, two 3's and one 4.
In total there are 14 + 5 + 2 + 1 = 22 divisors.
On the other hand all partitions of all positive integers <= 4 are as shown below:
.
. Partition Partitions Partitions Partitions
. of 1 of 2 of 3 of 4
.
. 4
. 2 2
. 3 3 1
. 2 2 1 2 1 1
. 1 1 1 1 1 1 1 1 1 1
.
In these partitions there are fourteen 1's, five 2's, two 3's and one 4.
In total there are 14 + 5 + 2 + 1 = A284870(4) = 22 parts.
Finally in accordance with the conjecture we can see that all divisors of all numbers in the 4th row of the triangle are the same positive integers as all parts of all partitions of all positive integers <= 4.
A340530
Irregular triangle read by rows T(n,k) in which row n has length is A000070(n-1) and every column k is A006218, (n >= 1, k >= 1).
Original entry on oeis.org
1, 3, 1, 5, 3, 1, 1, 8, 5, 3, 3, 1, 1, 1, 10, 8, 5, 5, 3, 3, 3, 1, 1, 1, 1, 1, 14, 10, 8, 8, 5, 5, 5, 3, 3, 3, 3, 3, 1, 1, 1, 1, 1, 1, 1, 16, 14, 10, 10, 8, 8, 8, 5, 5, 5, 5, 5, 3, 3, 3, 3, 3, 3, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 20, 16, 14, 14, 10, 10, 10, 8, 8, 8, 8, 8, 5, 5, 5, 5, 5, 5, 5
Offset: 1
Triangle begins:
1;
3, 1;
5, 3, 1, 1;
8, 5, 3, 3, 1, 1, 1;
10, 8, 5, 5, 3, 3, 3, 1, 1, 1, 1, 1;
14, 10, 8, 8, 5, 5, 5, 3, 3, 3, 3, 3, 1, 1, 1, 1, 1, 1, 1;
...
For n = 5 the length of row 5 is A000070(4) = 12.
The sum of row 5 is 10 + 8 + 5 + 5 + 3 + 3 + 3 + 1 + 1 + 1 + 1 + 1 = 42, equaling A284870(5).
Showing 1-5 of 5 results.
Comments