A067448 Smallest n-th power whose decimal expansion starts with 7.

7, 729, 729, 707281, 7776, 729, 78125, 78310985281, 794280046581, 79792266297612001, 743008370688, 7355827511386641, 793714773254144, 78364164096, 734461618571137961752599, 79766443076872509863361

Offset: 1

Author

Amarnath Murthy, Feb 05 2002

Keywords

• base
• easy
• nonn

Comments

Terms from Robert G. Wilson v.

Links

• Robert Israel, Table of n, a(n) for n = 1..597

Crossrefs

Cf. A067442, A067443, A067444, A067445, A067446, A067447.

Programs

Maple

f:= proc(n) local x, y;
  for x from 2 do
    y:= x^n;
    if floor(y/10^ilog10(y)) = 7 then return x^n fi
  od
end proc:
map(f, [$1..50]); # Robert Israel, Apr 02 2025

Mathematica

a = {}; Do[k = 1; While[First[IntegerDigits[k^n]] != 7, k++ ]; a = Append[a, k^n], {n, 1, 25}]; a (* Robert G. Wilson v *)