OFFSET
0,1
EXAMPLE
2 is not the sum of the nonprime divisors of any k.
5 is the sum of the nonprime divisors of 4 (1 + 4 = 5).
23 is the sum of the nonprime divisors of 12 (1 + 4 + 6 + 12) and of 22 (1 + 22).
83 is the sum of the nonprime divisors of 40 (1 + 4 + 8 + 10 + 20 + 40) and 52 (1 + 4 + 26 + 52) and 82 (1 + 82).
MAPLE
N:= 10^6: # for terms < 10^6
f:= proc(n) convert(remove(isprime, numtheory:-divisors(n)), `+`) end proc:
R:= Vector(N):
for i from 1 to N do
v:= f(i);
if v <= N then R[v]:= R[v]+1 fi
od:
m:= convert(R, set)[-2]:
V:= Array(0..m): count:= 0:
for i from 2 while count < m+1 do
if V[R[i]] = 0 then V[R[i]]:= i; count:= count+1 fi
od:
convert(V, list);
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Robert Israel, Sep 12 2024
STATUS
approved