login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A195410
Decimal expansion of normalized Philo sum, Philo(ABC,I), where I=incenter of the right triangle ABC having sidelengths (a,b,c)=(r-1,r,sqrt(3)), where r=(1+sqrt(5))/2 (the golden ratio).
5
4, 6, 2, 9, 9, 9, 2, 8, 1, 8, 7, 2, 9, 4, 5, 1, 4, 5, 2, 5, 2, 4, 9, 1, 5, 0, 8, 8, 0, 0, 5, 4, 7, 8, 7, 1, 6, 2, 5, 0, 7, 4, 6, 2, 2, 4, 2, 6, 4, 0, 6, 4, 3, 1, 7, 5, 1, 9, 0, 9, 4, 4, 8, 2, 9, 9, 3, 2, 7, 6, 6, 5, 8, 4, 3, 7, 5, 6, 1, 8, 7, 5, 0, 9, 0, 4, 1, 7, 1, 3, 4, 1, 1, 0, 7, 0, 4, 8, 4, 3, 7, 6
OFFSET
0,1
COMMENTS
See A195284 for definitions and a general discussion.
EXAMPLE
Philo(ABC,I)=0.4629992818729451452524915088005478716250...
MATHEMATICA
a = b - 1; b = (1 + Sqrt[5])/2; c = Sqrt[3];
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) A195407 *)
N[x2, 100]
RealDigits[%] (* (B) A195408 *)
N[x3, 100]
RealDigits[%] (* (C) A195409 *)
N[(x1 + x2 + x3)/(a + b + c), 100]
RealDigits[%] (* Philo(ABC, I) A195410 *)
CROSSREFS
Cf. A195284.
Sequence in context: A171547 A114579 A021220 * A095196 A074828 A282028
KEYWORD
nonn,cons
AUTHOR
Clark Kimberling, Sep 17 2011
EXTENSIONS
a(99) corrected by Georg Fischer, Jul 18 2021
STATUS
approved