C (gcc), 43 bytes

f(n,i){for(i=1;n%++i;);n=i<n&&f(n/i)^i?:i;} 

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Returns p if n is almost-prime, and 1 otherwise.

C (gcc), 43 bytes

f(n,i){for(i=1;n%++i;);n=i<n&&f(n/i)^i?:i;} 

Try it online!

Returns p if n is almost-prime, and 1 otherwise.

f(n,i){ for(i=1;n%++i;); // identify i = the least prime factor of n n=i<n&&f(n/i)^i // if n is neither prime nor almost-prime ? // return 1 :i; // return i }