OFFSET
1,1
EXAMPLE
sigma(27347) - 27347 = 30240 - 27347 = 2893 and sigma(7347) - 7347 = 10240 - 7347 = 2893.
MAPLE
with(numtheory): P:=proc(q) local a, k, n, p, x, y; for n from 2 to q do
if not isprime(n) then x:=n mod 10^(ilog10(n));
if sigma(n)-n=sigma(x)-x then print(n); fi; fi; od; end: P(10^6);
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Paolo P. Lava, Oct 10 2017
STATUS
approved