Ravenity of Cube Distance Numbers
Pyth - 21 19 18 bytes
I wonder if there's a trick.
l{st#mP+Q^d3s_BMSE
Test Suite.
l Length
{ Uniquify
s Combine divisor lists
t# Filter by if more than one element
PM Take prime factorization of each number
+RQ Add each num in list to input
s_BM Each num in list and its negative (with bifurcate)
^R3 Cube each num in list
SE Inclusive unary range - [1, 2, 3,... n] to input
Jelly, 16 bytes
ŒRḟ0*3+µÆfFœ-µQL
Takes x and n as command-line arguments, in that order. Try it online!
How it works
ŒRḟ0*3+µÆfFœ-µQL Main link. Arguments, x, n
ŒR Range; yield [-x, ..., x].
ḟ0 Filter out 0.
*3 Cube each remaining integer.
+ Add n to all cubes.
µ Begin a new, monadic link. Argument: A (list of sums)
Æf Factorize each k in A.
F Flatten the resulting, nested list.
œ- Perform multiset difference with A.
If k in A is prime, Æf returns [k], adding on k too many to the
flat list. Multiset difference with A removes exactly one k from
the results, thus getting rid of primes.
If k is composite (or 1), it cannot appear in the primes in the
flat list, so subtracting it does nothing.
µ Begin a new, monadic link. Argument: D (list of prime divisors)
Q Unique; deduplicate D.
L Compute the length of the result.
Julia, 107 bytes
f(n,x)=endof(∪(foldl(vcat,map(k->[keys(factor(k))...],filter(i->!isprime(i),[n+z^3for z=[-x:-1;1:x]])))))
This is a function that accepts two integers and returns an integer.
Ungolfed:
function f(n, x)
# Get all cube distance numbers
cubedist = [n + z^3 for z = [-x:-1; 1:x]]
# Filter out the primes and zeros
noprimes = filter(i -> !isprime(i) && i > 0, cubedist)
# Factor each remaining number
factors = map(k -> [keys(factor(k))...], noprimes)
# Flatten the list of factors
flat = foldl(vcat, factors)
# Return the number of unique elements
return endof(∪(flat))
end