OFFSET
1,1
EXAMPLE
V(3954) = 7249 and sigma(3954) = sigma(7249) = 7920.
MAPLE
with(numtheory): V:=proc(t) local j, w, x, y; x:=t; y:=[]; while x>0 do
y:=[x mod 10, op(y)]; x:=trunc(x/10); od; x:=(y[nops(y)]+y[1]) mod 10;
for j from 1 to nops(y)-1 do x:=x*10+((y[j]+y[j+1]) mod 10); od; x; end:
P:=proc(q) local n; for n from 10 to q do if sigma(n)=sigma(V(n))
then print(n); fi; od; end: P(10^10);
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Paolo P. Lava, Jul 23 2014
STATUS
approved