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A079940 Greedy fractional multiples of 1/e: a(1)=1, sum_{n>0} fractional_part(a(n)/e)). +0
6
1, 3, 4, 11, 87, 193, 386, 579, 1457, 23225, 49171, 98342, 147513, 196684, 566827, 13580623, 28245729, 56491458, 84737187, 112982916 (list; graph; listen)
OFFSET

1,2

COMMENT

The n-th greedy fractional multiple of x is the smallest integer m that does not cause sum(k=1..n,frac(m*x)) to exceed unity; an infinite number of terms appear as the denominators of the convergents to the continued fraction of 1/e.

After a(20), there is only 109305220 - 297122396/e = ~1.06317354345346734...*10^-8 to work with.

EXAMPLE

a(4) = 11 since frac(1x) + frac(3x) + frac(4x) + frac(11x) < 1, while frac(1x) + frac(3x) + frac(4x) + frac(k*x) > 1 for all k>4 and k<11.

MAPLE

Digits := 100: a := []: s := 0: x := 1.0/exp(1.0): for n from 1 to 1000000 do: temp := evalf(s+frac(n*x)): if (temp<1.0) then a := [op(a), n]: print(n): s := s+evalf(frac(n*x)): fi: od: a;

MATHEMATICA

a[1] = 1; a[n_] := a[n] = Block[{k = a[n - 1] + 1, ps = Plus @@ Table[ FractionalPart[ a[i]*E^-1], {i, n - 1}]}, While[ ps + FractionalPart[k*E^-1] > 1, k++ ]; a[n] = k]; Do[ Print[ a[n]], {n, 20}] (from Robert G. Wilson v Nov 03 2004)

CROSSREFS

Cf. A007676 (numerators of convergents to e), A079934, A079939, A079941.

Sequence in context: A101982 A041947 A102013 this_sequence A041299 A001112 A042079

Adjacent sequences: A079937 A079938 A079939 this_sequence A079941 A079942 A079943

KEYWORD

more,nonn

AUTHOR

Benoit Cloitre (benoit7848c(AT)orange.fr) and Paul D. Hanna (pauldhanna(AT)juno.com), Jan 21 2003

EXTENSIONS

More terms from Mark Hudson (mrmarkhudson(AT)hotmail.com), Jan 30 2003

a(16), a(17), a(18), a(19) & a(20) from Robert G. Wilson v (rgwv(AT)rgwv.com), Nov 03 2004

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Last modified November 24 23:16 EST 2009. Contains 167481 sequences.


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