|
|
A195144
|
|
Reversal of n equals the sum of the reversals of the anti-divisors of n.
|
|
2
|
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
Like A069942 but using anti-divisors. No other terms up to 3*10^10.
|
|
LINKS
|
|
|
EXAMPLE
|
The first two terms are banal cases: anti-divisors of 5 are 2 and 3 and their reversals are again 5, 2 and 3 and 2+3 = 5. The same for 8: 3+5 = 8. Anti-divisors of 895799 are 2, 3, 199, 597, 3001, 9003, 597199 and 2+3+991+795+1003+3009+991795 = 997598.
|
|
MAPLE
|
Rev:=proc(n)
local a, i, k;
i:=convert(n, base, 10); a:=0;
for k from 1 to nops(i) do a:=a*10+i[k]; od;
a;
end:
P:=proc(j)
local h, m, n, r;
for m from 3 to j do
h:=0;
for r from 2 to m-1 do
if abs((m mod r)-r/2)<1 then h:=h+Rev(r); print(r); fi;
od;
if h=Rev(m) then print(m); fi;
od;
end:
P(1000000);
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,hard,base,bref,more
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|