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 1-3 of 3 results.

A055918 Coefficients of a polynomial used in calculation of A055915.

Original entry on oeis.org

1, 8, 36, 156, 524, 1552, 4259, 10394, 24183, 51875, 106494, 206745, 384905, 687199, 1183788, 1963561, 3173730, 4927653, 7548433, 11034284, 16135051, 22312164, 31309061, 41115663, 55583921, 69539866, 90846746, 108550608, 137370735
Offset: 0

Views

Author

Christian G. Bower, Jun 22 2000

Keywords

Comments

Last term has index 80.

Extensions

Corrected by R. J. Mathar, Oct 31 2006

A055907 Triangle: number of directed site animals on hexagonal net (honeycomb) with n total sites and k sites supported in one particular way.

Original entry on oeis.org

0, 1, 1, 1, 2, 1, 1, 4, 4, 1, 1, 6, 10, 6, 1, 1, 9, 21, 20, 8, 1, 1, 12, 39, 53, 36, 10, 1, 1, 16, 67, 121, 128, 56, 12, 1, 1, 20, 107, 249, 388, 240, 74, 14, 1, 1, 25, 163, 471, 1050, 854, 331, 100, 16, 1, 1, 30, 238, 836, 2601, 2654, 1212, 511, 130, 18, 1, 1, 36, 337
Offset: 0

Views

Author

Christian G. Bower, Jun 14 2000

Keywords

Examples

			Table begins:
  0;
  1,  1;
  1,  2,  1;
  1,  4,  4,  1;
  1,  6, 10,  6,  1;
  ...
		

Crossrefs

Row sums give A055919.
Cf. A055898.

Extensions

Name edited by Andrey Zabolotskiy, Jun 21 2022

A331144 Irregular triangle read by rows: row n gives coefficients (in increasing order of powers of x) of normalized numerator polynomial of generating function for hexagonal net (honeycomb) directed site animals. Here n is the number of sites supported in one particular way.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 2, 4, 2, 0, 1, 1, 3, 4, 10, 12, 14, 16, 13, 14, 7, 6, 4, 0, 1, 1, 4, 8, 22, 37, 56, 88, 98, 137, 118, 145, 113, 104, 79, 50, 40, 17, 10, 6, 0, 1
Offset: 0

Views

Author

N. J. A. Sloane, Jan 13 2020

Keywords

Comments

Guttmann-Conway give coefficients for rows n <= 9.
This triangle just gives the numerators of the generating functions. Although it is not clear from their descriptions, it appears that A055907-A055915 give the expansions of the actual generating functions.

Examples

			Triangle begins:
1,
1,
1,1,1,
1,2,4,2,0,1,
1,3,4,10,12,14,16,13,14,7,6,4,0,1,
1,4,8,22,37,56,88,98,137,118,145,113,104,79,50,40,17,10,6,0,1
...
		

References

  • Guttmann, A. J., and A. R. Conway. "Hexagonal lattice directed site animals." Series on advances in statistical mechanics, 14.1 (1999): 491-504.

Crossrefs

Extensions

Name edited by Andrey Zabolotskiy, Jun 21 2022
Showing 1-3 of 3 results.