OFFSET
1,3
FORMULA
Equals 2*sqrt(3)*Sum_{n >= 1} x^(n^2)*(1 + x^(2*n))/(1 - x^(2*n)), where x = 2 - sqrt(3). - Peter Bala, Aug 24 2022
EXAMPLE
sum = 1.0898631708870032278893257211397258128825141977596999...
MAPLE
x := 2 - sqrt(3):
evalf(2*sqrt(3)*add(x^(n^2)*(1 + x^(2*n))/(1 - x^(2*n)), n = 1..13), 100); # Peter Bala, Aug 24 2022
MATHEMATICA
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Clark Kimberling, Dec 07 2015
STATUS
approved