OFFSET
1,2
COMMENTS
EXAMPLE
Anti-divisors of 208 are 3, 5, 32, 83, 139 and their sum is 262 ; sigma(208) = 434.
MAPLE
with(numtheory): T:=proc(w) local x, y, z; x:=w; y:=0; for z from 1 to ilog10(x)+1 do y:=10*y+(x mod 10); x:=trunc(x/10); od; y; end:
P:=proc(q) local a, j, k, n, t; print(1); for n from 1 to q do k:=0; j:=n;
while j mod 2 <> 1 do k:=k+1; j:=j/2; od;
a:=sigma(2*n+1)+sigma(2*n-1)+sigma(n/2^k)*2^(k+1)-6*n-2;
if T(a)=a and sigma(n)=T(sigma(n)) then print(n); fi; od; end: P(10^6);
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Paolo P. Lava, Jun 07 2016
EXTENSIONS
Missing a(1)-a(2) and a(17)-a(20) from Giovanni Resta, Jun 19 2016
a(21)-a(29) from Max Alekseyev, Jan 28 2024
STATUS
approved