OFFSET
1,1
COMMENTS
Another similar variation on Leyland numbers is k = x^y' + y^x' that leads to A014091.
EXAMPLE
2' = 1, 4' = 4, 1^4 + 4^2 = 1 + 16 = 17.
MAPLE
with(numtheory): N:= 10^5: A:={}: for x from 2 to floor(N^(1/2)) do
for y from 2 do yd:=y*add(op(2, p)/op(1, p), p=ifactors(y)[2]); xd:=x*add(op(2, p)/op(1, p), p=ifactors(x)[2]); a:= xd^y + yd^x;
if a>N then break fi; A:=A union {a}; od; od; sort([op(A)]);
# based on Robert Israel code in A076980.
CROSSREFS
KEYWORD
nonn
AUTHOR
Paolo P. Lava, Mar 31 2017
STATUS
approved