cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A346168 Primes p such that p*p! - 1 is prime.

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%I A346168 #28 Feb 12 2025 18:12:06
%S A346168 2,3,5,7,11,397,599,2239
%N A346168 Primes p such that p*p! - 1 is prime.
%C A346168 a(9) > 10^4.
%p A346168 select(p -> isprime(p) and isprime(p*factorial(p) - 1), [$2 .. 600])
%t A346168 Select[Range[2, 600], PrimeQ[#] && PrimeQ[#*#! - 1] &]
%t A346168 Select[Prime[Range[110]],PrimeQ[# #!-1]&] (* The program generates the first 7 terms of the sequence. *) (* _Harvey P. Dale_, Feb 12 2025 *)
%o A346168 (PARI) a = List(); for(p=2, 600, if(isprime(p) && isprime(p*p!-1), listput(a, p))); a
%o A346168 (Sage) [p for p in range(2, 600) if is_prime(p) and is_prime(p*factorial(p) - 1)]
%Y A346168 Prime terms of A090704.
%Y A346168 Cf. A001563, A090703, A188914, A346167.
%K A346168 nonn,more
%O A346168 1,1
%A A346168 _Reza K Ghazi_, Jul 08 2021