A291211 Numbers k>1 such that k*k^(1/k) is closer to an integer than for any smaller number.

2, 5, 6, 15, 16, 46, 135, 136, 385, 1072, 21976, 59813, 59814, 162682, 162683, 442329, 1202506, 3268905, 24154808, 65659807, 485164995, 1318815513, 1318815514, 26489121842, 72004899025, 195729609091, 532048240237, 1446257063899

Offset

1,1

Comments

The corresponding closest matching integers are given in A291212.

Links

Table of n, a(n) for n=1..28.

Example

Let s(x) = x*x^(1/x), r(x) = round(s(x)), d(x) = abs(s(x)-r(x));
a(1) = 2:
  s(2) = 2.8284271...,
  r(2) = A291212(1) = 3,
  d(2) = 0.17157...;
a(2) = 5:
  s(5) = 6.8986483...,
  r(5) = A291212(2) = 7,
  d(5) = 0.10135169...;
a(3) = 6:
  s(6) = 8.0880369...,
  r(6) = A291212(3) = 8,
  d(6) = 0.08803692...;
a(4) = 15:
  s(15) = 17.96790087...,
  r(15) = A291212(4) = 18,
  d(18) = 0.03209912...;
a(5) = 16:
  s(16) = 19.02731384...,
  r(16) = A291212(5) = 19,
  d(19) = 0.02731384...;

Crossrefs

Cf. A291210, A291212.

Sequence in context: A341373 A363132 A287203 * A193402 A193405 A037079

Adjacent sequences: A291208 A291209 A291210 * A291212 A291213 A291214

Keyword

nonn

Author

Hugo Pfoertner, Aug 21 2017

Status

approved