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A002668
Continued cotangent for e.
(Formerly M1900 N0748)
12
2, 8, 75, 8949, 119646723, 15849841722437093, 708657580163382065836292133774995, 529026553215766321676623343348414600292754204772300344704877695232
OFFSET
1,1
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).
LINKS
D. H. Lehmer, A cotangent analogue of continued fractions, Duke Math. J., 4 (1935), 323-340. [Annotated scanned copy]
Eric Weisstein's World of Mathematics, Lehmer Cotangent Expansion
MATHEMATICA
b[1] = E; b[n_] := b[n] = (b[n-1]*Floor[b[n-1]]+1) / (b[n-1]-Floor[b[n-1]]); a[n_] := Floor[b[n]]; Table[a[n], {n, 1, 8}] (* Jean-François Alcover, Jan 17 2012, after PARI *)
PROG
(PARI) { default(realprecision, 10000); bn=vector(11); bn[1]=exp(1); for(n=2, 11, bn[n]=(bn[n-1]*floor(bn[n-1]) + 1)/(bn[n-1] - floor(bn[n-1]))); for (n=1, 11, write("b002668.txt", n, " ", floor(bn[n]))); } \\ Harry J. Smith, May 04 2009
CROSSREFS
Sequence in context: A356746 A132039 A204552 * A193205 A303943 A295345
KEYWORD
nonn,easy,nice
EXTENSIONS
More terms from Jeffrey Shallit
STATUS
approved