A239479 Integer solutions of the arithmetic differential equation m' = m - sqrt(m).

1, 9, 441, 815409, 553613841

Offset: 1

Author

Paolo P. Lava, Mar 20 2014

Keywords

• nonn
• more

Comments

a(6) > 10^17. - Giovanni Resta, Mar 20 2014

m = k^2, where k satisfies k' = (k-1)/2. - Charlie Neder, Mar 08 2019

Examples

			For m = 441 we have that m' = 420, sqrt(441) = 21 and 420 = 441 - 21.
		

Crossrefs

Cf. A003415, A239478.

Programs

Maple

with(numtheory); P:= proc(q) local n,p,x;
for n from 1 to q do x:=n^2;
if x*add(op(2,p)/op(1,p),p=ifactors(x)[2])=n^2-n then print(n^2);
fi; od; end: P(10^9);