Anti-primes: Difference between revisions
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{{out}}
<pre>(1 2 4 6 12 24 36 48 60 120 180 240 360 720 840 1260 1680 2520 5040 7560)</pre>
=={{header|Prolog}}==
{{trans|Erlang}}<lang prolog>
divcount(N, Count) :- divcount(N, 1, 0, Count).
divcount(N, D, C, C) :- D*D > N, !.
divcount(N, D, C, Count) :-
succ(D, D2),
divs(N, D, A), plus(A, C, C2),
divcount(N, D2, C2, Count).
divs(N, D, 0) :- N mod D =\= 0, !.
divs(N, D, 1) :- D*D =:= N, !.
divs(_, _, 2).
antiprimes(N, L) :- antiprimes(N, 1, 0, [], L).
antiprimes(0, _, _, L, R) :- reverse(L, R), !.
antiprimes(N, M, Max, L, R) :-
divcount(M, Count),
succ(M, M2),
(Count > Max
-> succ(N0, N), antiprimes(N0, M2, Count, [M|L], R)
; antiprimes(N, M2, Max, L, R)).
main :-
antiprimes(20, X),
write("The first twenty semi-primes are "), write(X), nl,
halt.
?- main.
</lang>
{{out}}
<pre>
The first twenty semi-primes are [1,2,4,6,12,24,36,48,60,120,180,240,360,720,840,1260,1680,2520,5040,7560]
</pre>
=={{header|Python}}==
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