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.

A195380 Decimal expansion of normalized Philo sum, Philo(ABC,I), where I=incenter of a 1,sqrt(3),sqrt(1) right triangle ABC (angles 30, 60, 90).

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Sep 17 2011

Keywords

Comments

See A195284 for definitions and a general discussion.

Examples

			Philo(ABC,I)=0.55757017691709380372112914604292318...
		

Crossrefs

Cf. A195284.

Programs

  • Mathematica
    a = 1; b = Sqrt[3]; c = 2;
    f = 2 a*b/(a + b + c);
    x1 = Simplify[f*Sqrt[a^2 + (b + c)^2]/(b + c) ]
    x2 = Simplify[f*Sqrt[b^2 + (c + a)^2]/(c + a) ]
    x3 = f*Sqrt[2]
    N[x1, 100]
    RealDigits[%] (* (A) A195348 *)
    N[x2, 100]
    RealDigits[%] (* (B) A093821 *)
    N[x3, 100]
    RealDigits[%] (* (C) A120683 *)
    N[(x1 + x2 + x3)/(a + b + c), 100]
    RealDigits[%] (* A195380 *)