Almost prime: Difference between revisions

=={{header|Maxima}}==

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/* Predicate function that checks k-almost primality for given integer n and parameter k */

k_almost_primep(n,k):=if integerp((n)^(1/k)) and primep((n)^(1/k)) then true else

lambda([x],(length(ifactors(x))=k and unique(map(second,ifactors(x)))=[1]) or (length(ifactors(x))<k and apply("+",map(second,ifactors(x)))=k))(n)$

/* Function that given a parameter k1 returns the first len k1-almost primes */

k_almost_prime_count(k1,len):=block(

count:0,

while length(sublist(makelist(i,i,count),lambda([x],k_almost_primep(x,k1))))<len do (count:count+1),

sublist(makelist(i,i,count),lambda([x],k_almost_primep(x,k1))))$

/* Test cases */

k_almost_prime_count(1,10);

k_almost_prime_count(2,10);

k_almost_prime_count(3,10);

k_almost_prime_count(4,10);

k_almost_prime_count(5,10);

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{{out}}

<pre>

[2,3,5,7,11,13,17,19,23,29]

[4,6,9,10,14,15,21,22,25,26]

[8,12,18,20,27,28,30,42,44,45]

[16,24,36,40,54,56,60,81,84,88]

[32,48,72,80,108,112,120,162,168,176]

</pre>