A281389 Least k > 1 such that refactorable number k is an n-th power.
2, 9, 8, 625, 7776, 117649, 128, 6561, 1000000000, 25937424601, 362797056, 23298085122481, 2541865828329, 29192926025390625, 32768, 48661191875666868481, 16926659444736, 104127350297911241532841, 10000000000000000000, 278218429446951548637196401
Offset: 1
Keywords
Examples
a(4) = 625 because 625 = 5^4 is the least fourth power refactorable number that is greater than 1.
Links
- S. Colton, Refactorable Numbers - A Machine Invention, J. Integer Sequences, Vol. 2, 1999.
- Joshua Zelinsky, Tau Numbers: A Partial Proof of a Conjecture and Other Results , Journal of Integer Sequences, Vol. 5 (2002), Article 02.2.8
Programs
Formula
a(n) = A281495(n)^n.
Extensions
More terms from Giovanni Resta, Jan 22 2017