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A105459 Decimal expansion of Hlawka's Schneckenkonstante K = -2.157782... 1
2, 1, 5, 7, 7, 8, 2, 9, 9, 6, 6, 5, 9, 4, 4, 6, 2, 2, 0, 9, 2, 9, 1, 4, 2, 7, 8, 6, 8, 2, 9, 5, 7, 7, 7, 2, 3, 5, 0, 4, 1, 3, 9, 5, 9, 8, 6, 0, 7, 5, 6, 2, 4, 5, 5, 1, 5, 4, 8, 9, 5, 5, 5, 0, 8, 5, 8, 8, 6, 9, 6, 4, 6, 7, 9, 6, 6, 0, 6, 4, 8, 1, 4, 9, 6, 6, 9, 4, 2, 9, 8, 9, 4, 6, 3, 9, 6, 0, 8, 9, 8 (list; constant; graph; refs; listen; history; internal format)
OFFSET

1,1

REFERENCES

D. Brink, The spiral of Theodorus and sums of zeta-values at the half-integers, Amer. Math. Monthly (to appear).

P. J. Davis, Spirals from Theodorus to Chaos, A K Peters, Wellesley, MA, 1993.

E. Hlawka, Gleichverteilung und Quadratwurzelschnecke, Monatsh. Math., 89 (1980) 19-44.

FORMULA

sum_{x=1}^{n-1}\frac{1}{arctan(x)}=2\sqrt{n}+K+o(1).

CROSSREFS

Cf. A185051 for continued fraction expansion.

Sequence in context: A093545 A193762 A198422 * A183946 A005297 A014551

Adjacent sequences:  A105456 A105457 A105458 * A105460 A105461 A105462

KEYWORD

nonn,cons

AUTHOR

David Brink (brink(AT)math.ku.dk), Jun 13 2011

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Last modified February 13 22:36 EST 2012. Contains 205567 sequences.