cp's OEIS Frontend

A360490 a(n) = (1/2) * A241102(n).

%I A360490 #19 Feb 27 2023 11:23:27
%S A360490 109,433,172801,238573,363313,640333,1145773,1968301,2056753,3121201,
%T A360490 3577393,6588973,11197873,13079233,13381633,15431473,21676033,
%U A360490 26462701,34476301,37340353,43823053,48481201,54749953,56454733,90816013,96038893,102667501,128786113
%N A360490 a(n) = (1/2) * A241102(n).
%C A360490 Primes which are half the difference between 2 cubes of primes.
%C A360490 Primes of the form 3*m^2 + 1, where m is the average of a twin prime pair (A014574).
%C A360490 A subsequence of A243761 and a supersequence of A270249.
%F A360490 a(n) = (1/2) * A241102(n).
%e A360490 172801 is a term because 172801 = (241^3 - 239^3)/2, and 172801, 239 and 241 are all primes.
%o A360490 (Python)
%o A360490 from itertools import islice
%o A360490 from sympy import isprime, nextprime
%o A360490 def A360490_gen(): # generator of terms
%o A360490     p, q = 3**3, 5
%o A360490     while True:
%o A360490         if isprime(k:=(m:=q**3)-p>>1):
%o A360490             yield k
%o A360490         p, q = m, nextprime(q)
%o A360490 A360490_list = list(islice(A360490_gen(),20)) # _Chai Wah Wu_, Feb 27 2023
%Y A360490 Cf. A014574, A030078, A103739, A243761, A270249.
%K A360490 nonn
%O A360490 1,1
%A A360490 _Ya-Ping Lu_, Feb 09 2023