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A069139 Egyptian fraction for square root of 1/2. 25
2, 5, 141, 68575, 32089377154, 1644444237306316731482, 65593236350142721999718859354569312622907814, 55836140966941396682452590821074724094286247680248793718758259857815239633935672711970868 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..7.

Index entries for sequences related to Egyptian fractions

Eric Weisstein's World of Mathematics, Egyptian Fraction

FORMULA

a(n) =ceiling[1/sqrt(2)-Sum_i{i<n}1/a(i)]

EXAMPLE

a(3)=68575 since sqrt(1/2)=0.707106781186..., 1/2+1/5+1/141+1/68574=0.707106781368... (which is too much) and 1/2+1/5+1/141+1/68575=0.707106781155... (which is not too much).

MATHEMATICA

a = {}; k = N[1/Sqrt[2], 1000]; Do[s = Ceiling[1/k]; AppendTo[a, s]; k = k - 1/s, {n, 1, 10}]; a [From Artur Jasinski, Sep 22 2008]

CROSSREFS

Cf. A006487.

Sequence in context: A145620 A130412 A175525 * A155762 A307480 A062611

Adjacent sequences:  A069136 A069137 A069138 * A069140 A069141 A069142

KEYWORD

nonn

AUTHOR

Henry Bottomley, Apr 08 2002

STATUS

approved

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Last modified November 22 13:47 EST 2019. Contains 329393 sequences. (Running on oeis4.)