OFFSET
1,1
COMMENTS
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..5000
Pierre-Antoine Guihéneuf, Rotations Discrètes, Images des Mathématiques, CNRS, 2018. See 3-2*sqrt(2), the fractional part of this constant, about the loss of information when rotating an image.
FORMULA
Equals 3 + Sum_{k>=0} binomial(2*k,k)/((k+1) * 8^k). - Amiram Eldar, Aug 03 2020
Equals 4 + exp(-arccosh(3)). - Amiram Eldar, Jul 06 2023
Equals 4 + (2-sqrt(2))/(2+sqrt(2)). - Davide Rotondo, Jun 08 2024
EXAMPLE
7 - 2*sqrt(2) = 4.17157287525380990239...
MATHEMATICA
RealDigits[7-2*Sqrt[2], 10, 120][[1]] (* Harvey P. Dale, May 01 2012 *)
PROG
(PARI) 7 - 2*sqrt(2) \\ G. C. Greubel, Nov 28 2017
(Magma) [7 - 2*Sqrt(2)]; // G. C. Greubel, Nov 28 2017
CROSSREFS
KEYWORD
cons,nonn
AUTHOR
Klaus Brockhaus, Feb 26 2009
STATUS
approved