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 1-9 of 9 results.

A082640 Triangle T(m,n) read by rows: unimodular triangulations of the grid P(m,n), m,n > 0, n <= m.

Original entry on oeis.org

2, 6, 64, 20, 852, 46456, 70, 12170, 2822648, 736983568, 252, 182132, 182881520, 208902766788, 260420548144996, 924, 2801708, 12244184472, 61756221742966, 341816489625522032, 1999206934751133055518, 3432, 43936824, 839660660268, 18792896208387012, 464476385680935656240, 12169409954141988707186052, 332633840844113103751597995920
Offset: 1

Views

Author

Ralf Stephan, May 15 2003

Keywords

Comments

The limit of T(2,n)^(1/n) is (611+sqrt(73))/36. - Stepan Orevkov, Jan 31 2022

Examples

			Triangle begins:
    2;
    6,     64;
   20,    852,     46456;
   70,  12170,   2822648,    736983568;
  252, 182132, 182881520, 208902766788, 260420548144996;
  ...
		

Crossrefs

Row/columns 1..2 are A000984, A296165.
Row/columns 5..9 are A351484, A351485, A351486, A351487, A351488.
Row sums: A151686. - N. J. A. Sloane, Jun 02 2009

A351484 a(n) is the number of primitive triangulations of a 5 X n rectangle.

Original entry on oeis.org

252, 182132, 182881520, 208902766788, 260420548144996, 341816489625522032, 464476385680935656240, 645855159466371391947660, 913036902513499041820702784, 1306520849733616781789190513820, 1887591165891651253904039432371172, 2747848427721241461905176361078147168
Offset: 1

Views

Author

Stefano Spezia, Feb 12 2022

Keywords

Crossrefs

Cf. A082640 (m X n rectangle).

A351485 a(n) is the number of primitive triangulations of a 6 X n rectangle.

Original entry on oeis.org

924, 2801708, 12244184472, 61756221742966, 341816489625522032, 1999206934751133055518, 12169409954141988707186052, 76083336332947513655554918994, 484772512167266688498399632918196, 3131521959869770128138491287826065904, 20443767611927599823217291769468449488548
Offset: 1

Views

Author

Stefano Spezia, Feb 12 2022

Keywords

Crossrefs

Cf. A082640 (m X n rectangle).

A351486 a(n) is the number of primitive triangulations of a 7 X n rectangle.

Original entry on oeis.org

3432, 43936824, 839660660268, 18792896208387012, 464476385680935656240, 12169409954141988707186052, 332633840844113103751597995920, 9369363517501208819530429967280708, 269621109753732518252493257828413137272, 7880009979020501614060394747170100093057300, 233031642883906149386619647304562977586311372556
Offset: 1

Views

Author

Stefano Spezia, Feb 12 2022

Keywords

Crossrefs

Cf. A082640 (m X n rectangle).

A351487 a(n) is the number of primitive triangulations of an 8 X n rectangle.

Original entry on oeis.org

12870, 698607816, 58591381296256, 5831528022482629710, 645855159466371391947660, 76083336332947513655554918994, 9369363517501208819530429967280708, 1191064812882685539785713745400934044308, 155023302820254133629368881178138076738462112, 20527337238769032315796332007167102984745417344046
Offset: 1

Views

Author

Stefano Spezia, Feb 12 2022

Keywords

Crossrefs

Cf. A082640 (m X n rectangle).

A351480 Decimal expansion of (611 + sqrt(73))/36.

Original entry on oeis.org

1, 7, 2, 0, 9, 5, 5, 5, 6, 5, 9, 5, 9, 2, 1, 5, 3, 6, 4, 3, 5, 5, 1, 9, 9, 0, 2, 3, 1, 2, 8, 4, 4, 3, 6, 2, 8, 9, 8, 4, 9, 8, 4, 5, 9, 8, 1, 3, 7, 5, 9, 2, 4, 5, 0, 6, 7, 1, 9, 6, 8, 4, 7, 5, 7, 0, 4, 9, 2, 1, 2, 4, 6, 7, 2, 0, 3, 5, 3, 6, 0, 6, 6, 1, 4, 1, 1, 3, 8, 1
Offset: 2

Views

Author

Stefano Spezia, Feb 12 2022

Keywords

Examples

			17.2095556595921536435519902312844...
		

Crossrefs

Programs

  • Mathematica
    First[RealDigits[(611+Sqrt[73])/36,10,90]]

Formula

Equals lim_{n->oo} A082640(2, n)^(1/n).
Equals 288*x_2, where x_2 is the largest root of 5184*x^2 - 611*x + 18.

A351481 Decimal expansion of log_2((611 + sqrt(73))/36)/2.

Original entry on oeis.org

2, 0, 5, 2, 5, 6, 8, 9, 7, 1, 6, 1, 2, 7, 3, 5, 6, 6, 5, 1, 0, 7, 8, 7, 1, 5, 4, 0, 4, 7, 8, 6, 5, 5, 8, 7, 1, 0, 5, 3, 8, 4, 8, 7, 6, 2, 3, 7, 1, 2, 2, 1, 4, 3, 8, 8, 9, 2, 9, 8, 0, 3, 2, 7, 7, 4, 1, 7, 9, 0, 8, 2, 0, 0, 4, 1, 2, 0, 7, 1, 0, 4, 6, 5, 9, 3, 2, 3, 6, 3
Offset: 1

Views

Author

Stefano Spezia, Feb 12 2022

Keywords

Examples

			2.052568971612735665107871540478655871...
		

Crossrefs

Programs

  • Mathematica
    First[RealDigits[N[Log[2,(611+Sqrt[73])/36]/2,90]]]
  • PARI
    log((611 + sqrt(73))/36)/log(4) \\ Charles R Greathouse IV, Oct 31 2023

Formula

Equals log_2(alpha)/2, where alpha = lim_{n->oo} A082640(2, n)^(1/n).

A351482 Decimal expansion of lim_{n->oo} f(3, n)^(1/(3*n)), where f(m, n) is the number of primitive lattice triangulations of m X n rectangle.

Original entry on oeis.org

4, 2, 3, 9, 3, 6, 9, 4, 8, 1, 5, 4, 8, 0, 2, 5, 6, 7, 1, 8, 7, 7, 6, 2, 5, 7, 4, 2, 0, 4, 5, 2, 3, 5, 7, 7, 2, 1, 0, 0, 6, 9, 5, 7, 1, 1, 2, 5, 1, 7, 9, 5, 4, 9, 9, 8, 3, 0, 8, 0, 1, 6, 8, 7, 8, 3, 3, 3, 5, 8, 2, 3, 8, 2, 7, 6, 7, 2, 8, 9, 8, 7, 8, 3, 7, 0, 5, 4, 8
Offset: 1

Views

Author

Stefano Spezia, Feb 12 2022

Keywords

Examples

			4.2393694815480256718776257420452357721...
		

Crossrefs

A351483 Decimal expansion of log_2(lim_{n->oo} f(3, n)^(1/(3*n))), where f(m, n) is the number of primitive lattice triangulations of m X n rectangle.

Original entry on oeis.org

2, 0, 8, 3, 8, 4, 9, 7, 0, 9, 7, 2, 1, 0, 2, 3, 2, 0, 8, 2, 2, 4, 2, 1, 9, 2, 8, 9, 4, 9, 6, 1, 7, 0, 1, 3, 9, 6, 4, 8, 5, 1, 3, 4, 2, 3, 2, 4, 9, 5, 5, 2, 1, 3, 0, 7, 9, 9, 0, 5, 9, 9, 1, 8, 5, 5, 1, 7, 2, 9, 0, 6, 9, 2, 8, 1, 8, 0, 5, 2, 5, 1, 8, 6, 6, 5, 0, 8, 8
Offset: 1

Views

Author

Stefano Spezia, Feb 12 2022

Keywords

Examples

			2.0838497097210232082242192894961701...
		

Crossrefs

Showing 1-9 of 9 results.