Factorial primes: Difference between revisions

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 <small>Items 15-17 are shown in full because that's still shorter than 20+length("...")+20+length(" (NN digits)").<br>
 Aside: Unfortunately the relative performance falls off a cliff under pwa/p2js by the 320! mark, and it'd probably need a few minutes to get to the 30th.</small>
+=={{header|Python}}==
+{{libheader|gmpy2}}
+Takes about 32 seconds to find the first 33 factorial primes on my machine (Ryzen 5 1500X).
+<syntaxhighlight lang="python">
+from itertools import islice
+from typing import Iterable
+from typing import Tuple
+import gmpy2
+def factorials() -> Iterable[int]:
+    i: int = 1
+    n: int = 1
+    while True:
+        yield n
+        n *= i
+        i += 1
+def factorial_primes() -> Tuple[int, int, str]:
+    for i, n in enumerate(factorials()):
+        if gmpy2.is_prime(n - 1):
+            yield (i, n - 1, "-")
+        if gmpy2.is_prime(n + 1):
+            yield (i, n + 1, "+")
+def main(n=10) -> None:
+    print(f"First {n} factorial primes.")
+    for i, factorial_prime, op in islice(factorial_primes(), 1, n + 1):
+        s = str(factorial_prime)
+        if len(s) > 40:
+            s = f"{s[:20]}...{s[-20:]} ({len(s)} digits)"
+        print(f"{i}! {op} 1 = {s}")
+if __name__ == "__main__":
+    import sys
+    main(int(sys.argv[1]) if len(sys.argv) > 1 else 10)
+</syntaxhighlight>
+{{out}}
+<pre>
+First 33 factorial primes.
+! + 1 = 2
+! + 1 = 3
+! - 1 = 5
+! + 1 = 7
+! - 1 = 23
+! - 1 = 719
+! - 1 = 5039
+! + 1 = 39916801
+! - 1 = 479001599
+! - 1 = 87178291199
+! + 1 = 10888869450418352160768000001
+! - 1 = 265252859812191058636308479999999
+! - 1 = 263130836933693530167218012159999999
+! - 1 = 8683317618811886495518194401279999999
+! + 1 = 13763753091226345046...79581580902400000001 (44 digits)
+! - 1 = 52302261746660111176...24100074291199999999 (45 digits)
+! + 1 = 33452526613163807108...40751665152000000001 (50 digits)
+! + 1 = 44701154615126843408...03680000000000000001 (106 digits)
+! + 1 = 14518309202828586963...48000000000000000001 (114 digits)
+! - 1 = 10873661566567430802...99999999999999999999 (147 digits)
+! + 1 = 33931086844518982011...00000000000000000001 (191 digits)
+! + 1 = 30897696138473508879...00000000000000000001 (272 digits)
+! - 1 = 90036917057784373664...99999999999999999999 (298 digits)
+! + 1 = 21161033472192524829...00000000000000000001 (665 digits)
+! - 1 = 22889974601791023211...99999999999999999999 (675 digits)
+! + 1 = 51008644721037110809...00000000000000000001 (715 digits)
+! - 1 = 24840307460964707050...99999999999999999999 (815 digits)
+! + 1 = 16008630711655973815...00000000000000000001 (867 digits)
+! + 1 = 29063471769607348411...00000000000000000001 (940 digits)
+! - 1 = 67718096668149510900...99999999999999999999 (1051 digits)
+! - 1 = 14130200926141832545...99999999999999999999 (1260 digits)
+! + 1 = 19723152008295244962...00000000000000000001 (2188 digits)
+! - 1 = 55847687633820181096...99999999999999999999 (2490 digits)
+</pre>
 =={{header|Raku}}==