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 1-2 of 2 results.

A143313 Triangle read by rows, A130540 * A000012, 1<=k<=n.

Original entry on oeis.org

1, 4, 1, 5, 1, 1, 11, 4, 1, 1, 7, 1, 1, 1, 1, 20, 8, 4, 1, 1, 19, 1, 1, 1, 1, 1, 1, 26, 11, 4, 4, 1, 1, 1, 1, 18, 5, 5, 1, 1, 1, 1, 1, 1, 28, 10, 4, 4, 4, 1, 1, 1, 1, 1, 13, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 55, 27, 15, 8, 4, 4, 1, 1, 1, 1, 1, 1, 15, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
Offset: 1

Views

Author

Gary W. Adamson, Aug 06 2008

Keywords

Comments

Left border = A007429: (1, 4, 5, 11, 7, 20, 9,...).
Row sums = A060640: (1, 5, 7, 17, 11, 35,...).

Examples

			First few rows of the triangle =
1;
4, 1;
5, 1, 1;
11, 4, 1, 1;
7, 1, 1, 1, 1;
20, 8, 4, 1, 1, 1;
9, 1, 1, 1, 1, 1, 1;
...
Row 4 = (11, 4, 1, 1) since row 4 of A130540 = (7, 3, 0, 1).
		

Crossrefs

Formula

Triangle read by rows, A130540 * A000012, 1<=k<=n. Equals partial row sums of A130540 starting from the right.

A329323 Triangle read by rows: T(n,k) is the sum of the parts congruent to 0 mod k in the partitions of n into equal parts, 1 <= k <= n.

Original entry on oeis.org

1, 4, 2, 6, 0, 3, 12, 8, 0, 4, 10, 0, 0, 0, 5, 24, 12, 12, 0, 0, 6, 14, 0, 0, 0, 0, 0, 7, 32, 24, 0, 16, 0, 0, 0, 8, 27, 0, 18, 0, 0, 0, 0, 0, 9, 40, 20, 0, 0, 20, 0, 0, 0, 0, 10, 22, 0, 0, 0, 0, 0, 0, 0, 0, 0, 11, 72, 48, 36, 24, 0, 24, 0, 0, 0, 0, 0, 12, 26, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 13, 56, 28, 0, 0
Offset: 1

Views

Author

Omar E. Pol, Nov 21 2019

Keywords

Comments

Column k lists the terms of A038040 multiplied by k and interspersed with (k-1) zeros.

Examples

			Triangle begins:
   1;
   4,  2;
   6,  0,  3;
  12,  8,  0,  4;
  10,  0,  0,  0,  5;
  24, 12, 12,  0,  0,  6;
  14,  0,  0,  0,  0,  0,  7;
  32, 24,  0, 16,  0,  0,  0,  8;
  27,  0, 18,  0,  0,  0,  0,  0,  9;
  40, 20,  0,  0, 20,  0,  0,  0,  0, 10;
  22,  0,  0,  0,  0,  0,  0,  0,  0,  0, 11;
  72, 48, 36, 24,  0, 24,  0,  0,  0,  0,  0, 12;
  26,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 13;
  56, 28,  0,  0,  0,  0, 28,  0,  0,  0,  0,  0,  0, 14;
  60,  0, 30,  0, 30,  0,  0,  0,  0,  0,  0,  0,  0,  0, 15;
  80, 64,  0, 48,  0,  0,  0, 32,  0,  0,  0,  0,  0,  0,  0, 16;
...
For n = 6 the partitions of 6 into equal parts are [6], [3, 3], [2, 2, 2], [1, 1, 1, 1, 1, 1]. Then, for k = 2 the sum of the parts that are multiples of 2 is 6 + 2 + 2 + 2 = 12, so T(6,2) = 12.
		

Crossrefs

Column 1 is A038040.
Row sums give A034718.
Leading diagonal gives A000027.
The number of positive terms in row n is A000005(n).

Formula

T(n,k) = A126988(n,k)*A134577(n,k).
Showing 1-2 of 2 results.