A018865 Smallest power of 7 that begins with n.

1, 2401, 343, 49, 5764801, 678223072849, 7, 823543, 96889010407, 107006904423598033356356300384937784807, 117649, 129934811447123020117172145698449, 13841287201, 1481113296616977741464105532513750734030421355207

Offset: 1

Author

David W. Wilson

Keywords

• nonn
• base

Links

• Seiichi Manyama, Table of n, a(n) for n = 1..237

Crossrefs

Cf. A018802 (k=2), A018857 (k=3), A018859 (k=4), A018861 (k=5), A018863 (k=6), this sequence (k=7), A018867 (k=8), A018869 (k=9).

Formula

a(n) = 7^A018866(n). - Seiichi Manyama, Jan 30 2017

a(7^n) = 7^n for n >= 0. - Seiichi Manyama, Jan 30 2017

Extensions

One more term (a(14)) from Harvey P. Dale, Mar 04 2014