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.

Previous Showing 41-43 of 43 results.

A259449 Triangle read by rows arising from enumeration of partitions into non-integral powers.

Original entry on oeis.org

1, 2, 5, 1, 8, 5, 11, 12, 1, 14, 23, 5, 18, 39, 16, 22, 62, 38, 3, 27, 91, 74, 12, 31, 127, 133, 33
Offset: 1

Views

Author

N. J. A. Sloane, Jun 27 2015

Keywords

Examples

			Triangle begins:
1,
2,
5,1,
8,5,
11,12,1,
14,23,5,
18,39,16,
22,62,38,3,
27,91,74,12,
31,127,133,33,
...
		

Crossrefs

Columns include A000093, A000327.

A259450 Triangle read by rows arising from enumeration of partitions into non-integral powers.

Original entry on oeis.org

1, 4, 9, 3, 16, 14, 25, 39, 6, 36, 91, 32, 49, 173, 109, 8, 64, 307, 288, 47, 81, 502, 654, 194, 5, 100, 779, 1337, 592, 45
Offset: 1

Views

Author

N. J. A. Sloane, Jun 27 2015

Keywords

Examples

			Triangle begins:
1,
4,
9,3,
16,14,
25,39,6,
36,91,32,
49,173,109,8,
64,307,288,47,
81,502,654,194,5,
100,779,1337,592,45,
...
		

Crossrefs

Columns include A000263, A000397.

A341822 Length of the longest 2-increasing sequence of positive integer triples with entries <= n.

Original entry on oeis.org

1, 2, 4, 8, 10, 14, 17, 21, 27, 30, 35
Offset: 1

Views

Author

Marcel K. Goh, Feb 20 2021

Keywords

Comments

A triple t=(a_1,a_2,a_3) is defined to be 2-less than a triple u=(b_1,b_2,b_3) if a_i < b_i for at least two coordinates i. A sequence t^(j) of triples is 2-increasing if for all i < j, t^(i) is 2-less than t^(j).
Terms n <= 5 have been confirmed by brute-force search (Table 1 of Gowers and Long (2021)).

Examples

			For n=4, the sequence (1,1,1), (1,2,2), (2,1,3), (2,2,4), (3,3,1), (3,4,2), (4,3,3), (4,4,4) has length a(4)=8 and every 2-increasing sequence of length 9 must contain a triple with some coordinate equal to 5.
		

References

  • W. T. Gowers and J. Long, The length of an s-increasing sequence of r-tuples, Combinatorics, Probability and Computing 30 (2021), 1-36.

Crossrefs

Cf. A000093.

Formula

a(n) >= n^{3/2} when n is a perfect square.
It is conjectured that a(n) <= n^{3/2} for all n.

Extensions

Edited by N. J. A. Sloane, Mar 21 2021
a(10)-a(11) and confirmation of previous terms by Bert Dobbelaere, Mar 27 2021
Previous Showing 41-43 of 43 results.