OFFSET
1,2
COMMENTS
Fixed points of A008477.
a(3) = 16 is the only term of the form p^q with p <> q. - Bernard Schott, Mar 28 2021
EXAMPLE
16 = 2^4 = 4^2.
27 = 3^3.
108 = 2^2*3^3.
6272 = 2^7*7^2.
121500 = 2^2 * 3^5*5^3.
MATHEMATICA
f[n_] := Product[{p, e} = pe; e^p, {pe, FactorInteger[n]}];
Reap[For[n = 1, n <= 10^8, n++, If[f[n] == n, Print[n]; Sow[n]]]][[2, 1]] (* Jean-François Alcover, Mar 29 2021 *)
PROG
(PARI) for(n=2, 10^8, if(n==prod(i=1, omega(n), component(component(factor(n), 2), i)^component(component(factor(n), 1), i)), print1(n, ", ")))
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from David W. Wilson
a(34)-a(36) from Jean-François Alcover, Mar 29 2021
STATUS
approved