|
%I #57 Jan 27 2017 13:19:23
%S 2,9,8,625,7776,117649,128,6561,1000000000,25937424601,362797056,
%T 23298085122481,2541865828329,29192926025390625,32768,
%U 48661191875666868481,16926659444736,104127350297911241532841,10000000000000000000,278218429446951548637196401
%N Least k > 1 such that refactorable number k is an n-th power.
%H S. Colton, <a href="https://cs.uwaterloo.ca/journals/JIS/colton/joisol.html">Refactorable Numbers - A Machine Invention</a>, J. Integer Sequences, Vol. 2, 1999.
%H Joshua Zelinsky, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL5/Zelinsky/zelinsky9.html">Tau Numbers: A Partial Proof of a Conjecture and Other Results </a>, Journal of Integer Sequences, Vol. 5 (2002), Article 02.2.8
%F a(n) = A281495(n)^n.
%e a(4) = 625 because 625 = 5^4 is the least fourth power refactorable number that is greater than 1.
%o (PARI) isA033950(n) = n % numdiv(n) == 0;
%o a(n) = {my(k=2); while (!isA033950 (k^n), k++); k^n; }
%Y Cf. A001597, A007947, A033950, A036907, A235524, A281495.
%K nonn
%O 1,1
%A _Altug Alkan_, Jan 21 2017
%E More terms from _Giovanni Resta_, Jan 22 2017
|
