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A188658 Decimal expansion of (1+sqrt(101))/10. 4
1, 1, 0, 4, 9, 8, 7, 5, 6, 2, 1, 1, 2, 0, 8, 9, 0, 2, 7, 0, 2, 1, 9, 2, 6, 4, 9, 1, 2, 7, 5, 9, 5, 7, 6, 1, 8, 6, 9, 4, 5, 0, 2, 3, 4, 7, 0, 0, 2, 6, 3, 7, 7, 2, 9, 0, 5, 7, 2, 8, 2, 8, 2, 9, 7, 3, 2, 8, 4, 9, 1, 2, 3, 1, 5, 5, 1, 9, 7, 0, 3, 8, 1, 2, 3, 6, 1, 7, 7, 6, 9, 2, 4, 5, 3, 9, 5, 2, 3, 5, 2, 3, 6, 6, 2, 9, 9, 5, 0, 3, 2, 6, 5, 2, 6, 1, 3, 2, 3, 1, 8, 8, 1, 5, 9, 3, 5, 8, 5, 7 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET
1,4
COMMENTS
Decimal expansion of the shape of a (1/5)-extension rectangle; see A188640 for definitions of shape and r-extension rectangle. Briefly, shape=length/width, and an r-extension rectangle is composed of two rectangles of shape 1/r when r<1.
The continued fraction is 1, 9, 1, 1, 9, 1, 1, 9, 1, 1, 9, 1, 1, 9, 1...
LINKS
Clark Kimberling, A Visual Euclidean Algorithm, The Mathematics Teacher 76 (1983) 108-109.
FORMULA
Equals exp(arcsinh(1/10)). - Amiram Eldar, Jul 04 2023
EXAMPLE
1.104987562112089027021926491275957618694502347002...
MATHEMATICA
r = 1/5; t = (r + (4 + r^2)^(1/2))/2; FullSimplify[t]
N[t, 130]
RealDigits[N[t, 130]][[1]]
ContinuedFraction[t, 120]
RealDigits[(1+Sqrt[101])/10, 10, 150][[1]] (* Harvey P. Dale, Nov 29 2020 *)
CROSSREFS
Cf. A188640.
Sequence in context: A199203 A197580 A081382 * A248803 A019784 A276539
KEYWORD
nonn,cons
AUTHOR
Clark Kimberling, Apr 10 2011
EXTENSIONS
a(130) corrected by Georg Fischer, Apr 02 2020
STATUS
approved

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Last modified March 29 04:23 EDT 2024. Contains 371264 sequences. (Running on oeis4.)