The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A081793 Continued cotangent for tanh(1). 0
 0, 1, 7, 135, 35445, 44465908998, 5112887721516309845621, 75234509360529020708450352828794956245887456, 5786575206590910267083400178061771765781639734324927167565054640197289842752623499343753 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 REFERENCES D. H. Lehmer, A cotangent analogue of continued fractions, Duke Math. J., 4 (1935), 323-340. LINKS FORMULA tanh(1)=cot(sum(n>=0, n, (-1)^n*acot(a(n))); let b(0)=tanh(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]=tanh(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 Cf. A002666, A002667, A002668. Sequence in context: A143181 A183478 A292395 * A296595 A210028 A243684 Adjacent sequences:  A081790 A081791 A081792 * A081794 A081795 A081796 KEYWORD nonn AUTHOR Benoit Cloitre, Apr 10 2003 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 1 16:44 EST 2021. Contains 349430 sequences. (Running on oeis4.)