OFFSET
1,1
REFERENCES
Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, p. 14.
EXAMPLE
Let w(n) = e - n/(n!)^(1/n). Approximations are shown here:
n .... w(n) ...... 1/n
1 .... 1.71828 .... 1
2 .... 1.30407 .... 0.5
3 .... 1.06732 .... 0.333333
4 .... 0.911078 ... 0.25
5 .... 0.799022 ... 0.2
10 ... 0.510157 ... 0.1
11 ... 0.477609 ... 0.090909
a(2) = 11 because w(11) < 1/2 < w(10).
MATHEMATICA
$MaxExtraPrecision = Infinity;
z = 1000; p[k_] := p[k] = k/(k!)^(1/k) (* Finch p. 14 *)
N[Table[E - p[n], {n, 1, z}]];
f[n_] := f[n] = Select[Range[z], E - p[#] < 1/n &, 1];
u = Flatten[Table[f[n], {n, 1, z/10}]] (* A247988 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Sep 29 2014
STATUS
approved