OFFSET
0,3
REFERENCES
D. H. Lehmer, A cotangent analogue of continued fractions, Duke Math. J., 4 (1935), 323-340.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
J. W. Wrench, Jr., personal communication.
LINKS
D. H. Lehmer, A cotangent analogue of continued fractions, Duke Math. J., 4 (1935), 323-340. [Annotated scanned copy]
J. W. Wrench, Jr., Letters to N. J. A. Sloane, Feb 1974
MATHEMATICA
Block[{$MaxExtraPrecision=1000}, Numerator[Convergents[With[{nn=15}, Cot[ Total[Last[#] ArcCot[First[#]]&/@Thread[{NestList[#^2+#+1&, 0, nn], PadRight[{}, nn+1, {1, -1}]}]]]], 10]]] (* Harvey P. Dale, Jan 29 2012 *)
CROSSREFS
KEYWORD
nonn,frac,nice
AUTHOR
STATUS
approved