OFFSET
1,1
COMMENTS
Decimal expansion of the length/width ratio of a sqrt(28)-extension rectangle. See A188640 for definitions of shape and r-extension rectangle.
A sqrt(28)-extension rectangle matches the continued fraction [5,2,9,5,2,687,6,4,1,2,2,...] for the shape L/W=sqrt(7)+sqrt(8). This is analogous to the matching of a golden rectangle to the continued fraction [1,1,1,1,1,1,1,1,...]. Specifically, for the sqrt(28)-extension rectangle, 5 squares are removed first, then 2 squares, then 9 squares, then 5 squares,..., so that the original rectangle of shape sqrt(7)+sqrt(8) is partitioned into an infinite collection of squares.
EXAMPLE
5.47417843581078068810499320205865658284960293...
MATHEMATICA
r = 28^(1/2); t = (r + (4 + r^2)^(1/2))/2; FullSimplify[t]
N[t, 130]
RealDigits[N[t, 130]][[1]]
ContinuedFraction[t, 120]
RealDigits[Sqrt[7]+Sqrt[8], 10, 150][[1]] (* Harvey P. Dale, Jun 07 2017 *)
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Clark Kimberling, Apr 13 2011
STATUS
approved