OFFSET
0,2
REFERENCES
D. H. Lehmer, A cotangent analogue of continued fractions, Duke Math. J., 4 (1935), 323-340.
FORMULA
cosh(1)=cot(sum(n>=0, n, (-1)^n*acot(a(n))); let b(0)=cosh(1), b(n)=(b(n-1)*floor(b(n-1))+1)/(b(n-1)-floor(b(n-1)) then a(n)=floor(b(n))
PROG
(PARI) ?bn=vector(100); b(n)=if(n<0, 0, bn[n]); bn[1]=cosh(1); ?for(n=2, 10, bn[n]=(b(n-1)*floor(b(n-1))+1)/(b(n-1)-floor(b(n-1)))) ?a(n)=floor(b(n+1))
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Apr 10 2003
STATUS
approved