Reza K Ghazi has authored 6 sequences.
A346168
Primes p such that p*p! - 1 is prime.
Original entry on oeis.org
2, 3, 5, 7, 11, 397, 599, 2239
Offset: 1
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select(p -> isprime(p) and isprime(p*factorial(p) - 1), [$2 .. 600])
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Select[Range[2, 600], PrimeQ[#] && PrimeQ[#*#! - 1] &]
Select[Prime[Range[110]],PrimeQ[# #!-1]&] (* The program generates the first 7 terms of the sequence. *) (* Harvey P. Dale, Feb 12 2025 *)
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a = List(); for(p=2, 600, if(isprime(p) && isprime(p*p!-1), listput(a, p))); a
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[p for p in range(2, 600) if is_prime(p) and is_prime(p*factorial(p) - 1)]
A346167
Primes p such that p*p! + 1 is also prime.
Original entry on oeis.org
2, 3, 5, 7, 19, 23, 149, 151, 197, 37691
Offset: 1
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select(p -> isprime(p) and isprime(p*factorial(p) + 1), [$2 .. 200]);
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Select[Range[2, 200], PrimeQ[#] && PrimeQ[#*#! + 1] &]
Select[Prime[Range[100]],PrimeQ[#*#!+1]&] (* Harvey P. Dale, Mar 21 2025 *)
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a = List(); for(p=2, 200, if(isprime(p) && isprime(p*p!+1), listput(a, p))); a
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[p for p in range(2, 200) if is_prime(p) and is_prime(p*factorial(p) + 1)]
A344991
Numbers k such that (2*k+1)*k!-1 is prime.
Original entry on oeis.org
1, 3, 5, 15, 20, 44, 45, 73, 80, 93, 295, 5395
Offset: 1
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select(k -> isprime((2*k+1)*k!-1), [$1 .. 300])[];
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Do[If[PrimeQ[(2*k + 1)*Factorial[k] - 1], Print[k]], {k, 1, 3000}]
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for(k=1, 3000, if(isprime((2*k+1)*k!-1), print1(k", ")))
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for k in range(1, 3000):
if is_prime((2*k+1)*factorial(k) - 1):
print(k)
A344963
Numbers k such that (2*k+1)*k!+1 is prime.
Original entry on oeis.org
0, 2, 3, 5, 11, 18, 68, 77, 124, 173, 205, 293, 1037, 1530, 1905, 2342, 3401, 4372, 4679, 5385
Offset: 1
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select(k -> isprime((2*k+1)*k!+1), [$0 .. 300])[];
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Do[If[PrimeQ[(2*k + 1)*Factorial[k] + 1], Print[k]], {k, 0, 3000}]
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for(k=0, 3000, if(isprime((2*k+1)*k!+1), print1(k", ")))
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for k in range(3000):
if is_prime((2*k+1)*factorial(k) + 1):
print(k)
A344170
Numbers k such that 3^(2*k+1) - 3^k - 1 is prime.
Original entry on oeis.org
1, 2, 5, 6, 7, 10, 17, 25, 31, 88, 95, 137, 141, 416, 610, 781, 800, 2353, 7291, 9627, 9749, 15946, 19215
Offset: 1
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for k from 1 to 3000 do if isprime(3^(2*k + 1) - 3^k - 1) then print(k); end if; end do
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Do[If[PrimeQ[3^(2k + 1) - 3^k - 1], Print[k]], {k, 1, 3000}]
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for(k=1, 3e3, if(isprime(3^(2*k+1)-3^k-1), print1(k", ")))
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for k in range(1, 3000):
if is_prime(3^(2 * k + 1) - 3^k - 1):
print(k)
A344263
Numbers m such that 3^(2m+1) - 3^m + 1 is prime.
Original entry on oeis.org
0, 3, 4, 11, 35, 56, 88, 104, 476, 1367, 1707, 2472, 22232, 25260
Offset: 1
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for m from 0 to 3000 do if isprime(3^(2*m + 1) - 3^m + 1) then print(m); end if; end do;
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Do[If[PrimeQ[3^(2 m + 1) - 3^m + 1], Print[m]], {m, 0, 3000}]
Select[Range[0,2500],PrimeQ[3^(2#+1)-3^#+1]&] (* Harvey P. Dale, Mar 01 2023 *)
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for(m=0, 3e3, if(isprime(3^(2*m+1)-3^m+1), print1(m", ")))
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for m in range(3000):
if is_prime(3^(2*m + 1) - 3^m + 1):
print(m)
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