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 1-6 of 6 results.

A140239 Decimal expansion of 3*sqrt(15)/4.

Original entry on oeis.org

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

Views

Author

Rick L. Shepherd, May 14 2008

Keywords

Comments

Area of the obtuse scalene triangle with sides of lengths 2, 3 and 4, the scalene triangle with least integer side lengths.
This is the area of the ninth-smallest triangle with integer side lengths, or the eighth-smallest triangle if two smaller triangles with the same area are counted only once (see A331251). - Hugo Pfoertner, Feb 12 2020

Examples

			2.90473750965556266388444904983679970812469127896869311994068032458511231895...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[(3Sqrt[15])/4,10,120][[1]] (* Harvey P. Dale, Apr 03 2013 *)

Formula

3*sqrt(15)/4 = 3*A010472/4.

A140246 Decimal expansion of sqrt(15)/6.

Original entry on oeis.org

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

Views

Author

Rick L. Shepherd, May 14 2008

Keywords

Comments

Inradius of the obtuse scalene triangle with sides of lengths 2, 3 and 4, the scalene triangle with least integer side lengths. Per the Weisstein link, the inradius is the area divided by the semiperimeter.

Examples

			0.64549722436790281419654423329706660180548695088193180443126229435224718198...
		

Crossrefs

Equals sqrt(A331257(8)/A331258(8)) (squared inradii of triangles with integer sides).

Programs

  • Mathematica
    RealDigits[Sqrt[15]/6,10,120][[1]] (* Harvey P. Dale, Mar 31 2013 *)
  • PARI
    sqrt(15)/6

Formula

sqrt(15)/6 = A010472/6 = 2*A140239/9.

A140248 Decimal expansion of 0.3 * sqrt(15).

Original entry on oeis.org

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

Views

Author

Rick L. Shepherd, May 14 2008

Keywords

Comments

Exradius opposite the side of length 2 of the obtuse scalene triangle with sides of lengths 2, 3 and 4, the scalene triangle with least integer side lengths. See formulas in the Weisstein link.
Multiplied by 10, this is sqrt(135). - Alonso del Arte, Jan 06 2013

Examples

			1.16189500386222506555377961993471988324987651158747724797627212983404492758...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[(3/10)Sqrt[15], 10, 105][[1]] (* Alonso del Arte, Jan 06 2013 *)
  • PARI
    0.3*sqrt(15)

Formula

0.3*sqrt(15) = 0.3*A010472 = 0.4*A140239 = 0.6*A088543 = 0.2*A140249.

A140247 Decimal expansion of 8/sqrt(15).

Original entry on oeis.org

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

Views

Author

Rick L. Shepherd, May 14 2008

Keywords

Comments

Circumradius of the obtuse scalene triangle with sides of lengths 2, 3 and 4, the scalene triangle with least integer side lengths. See formulas in the Weisstein link.

Examples

			2.06559111797728900542894154655061312577755824282218177418003934192719098236...
		

Crossrefs

Equals sqrt(A331227(10)/A331228(10)) = sqrt(A331227(11)/A331228(11)), A331254, A331255, A331256 (list of triangles with integer sides sorted by circumradius).

Programs

  • Mathematica
    RealDigits[8/Sqrt[15],10,120][[1]] (* Harvey P. Dale, May 06 2012 *)
  • PARI
    8/sqrt(15)

Formula

8/sqrt(15) = 8/A010472.

A140249 Decimal expansion of 3*sqrt(15)/2.

Original entry on oeis.org

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

Views

Author

Rick L. Shepherd, May 14 2008

Keywords

Comments

Exradius opposite the side of length 4 of the obtuse scalene triangle with sides of lengths 2, 3 and 4, the scalene triangle with least integer side lengths. See formulas in the Weisstein link.

Examples

			5.80947501931112532776889809967359941624938255793738623988136064917022463790...
		

Crossrefs

Programs

  • Mathematica
    First[RealDigits[3 Sqrt[15]/2,10,100]] (* Paolo Xausa, Oct 30 2023 *)
  • PARI
    3*sqrt(15)/2

Formula

3*sqrt(15)/2 = 3*A010472/2 = 2*A140239 = 3*A088543 = 5*A140248.

A176058 Decimal expansion of (3+sqrt(15))/2.

Original entry on oeis.org

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

Views

Author

Klaus Brockhaus, Apr 07 2010

Keywords

Comments

Continued fraction expansion of (3+sqrt(15))/2 is A176059.

Examples

			(3+sqrt(15))/2 = 3.43649167310370844258...
		

Crossrefs

Cf. A010472 (decimal expansion of sqrt(15)), A176059 (repeat 3, 2).

Programs

  • Mathematica
    First[RealDigits[(3 + Sqrt[15])/2, 10, 100]] (* Paolo Xausa, Jun 18 2024 *)

Formula

Equals 1.5 + A088543. [R. J. Mathar, Apr 12 2010]
Showing 1-6 of 6 results.