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.

A336452 Triangle read by rows, the Riordan square of the number of achiral m-color cyclic compositions of n (A308747). T(n,k) for 1 <= k <= n.

Original entry on oeis.org

1, 3, 3, 6, 15, 9, 13, 49, 63, 27, 23, 137, 276, 243, 81, 44, 338, 969, 1323, 891, 243, 73, 782, 2950, 5589, 5778, 3159, 729, 131, 1695, 8161, 20097, 28485, 23733, 10935, 2187, 210, 3545, 20966, 64557, 117801, 133569, 93312, 37179, 6561
Offset: 1

Views

Author

Peter Luschny, Aug 09 2020

Keywords

Comments

See the link and A321620 for more information about the Riordan square transform.

Examples

			[1] [   1]
[2] [   3,    3]
[3] [   6,   15,     9]
[4] [  13,   49,    63,    27]
[5] [  23,  137,   276,   243,     81]
[6] [  44,  338,   969,  1323,    891,    243]
[7] [  73,  782,  2950,  5589,   5778,   3159,   729]
[8] [ 131, 1695,  8161, 20097,  28485,  23733, 10935,  2187]
[9] [ 210, 3545, 20966, 64557, 117801, 133569, 93312, 37179, 6561]
		

Crossrefs

Programs

  • SageMath
    # using riordan_square_array from A321620, A308747.
    riordan_square_array([1, 3, 6, 13, 23, 44, 73, 131, 210])