A360490 a(n) = (1/2) * A241102(n).
109, 433, 172801, 238573, 363313, 640333, 1145773, 1968301, 2056753, 3121201, 3577393, 6588973, 11197873, 13079233, 13381633, 15431473, 21676033, 26462701, 34476301, 37340353, 43823053, 48481201, 54749953, 56454733, 90816013, 96038893, 102667501, 128786113
Offset: 1
Keywords
Examples
172801 is a term because 172801 = (241^3 - 239^3)/2, and 172801, 239 and 241 are all primes.
Programs
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Python
from itertools import islice from sympy import isprime, nextprime def A360490_gen(): # generator of terms p, q = 3**3, 5 while True: if isprime(k:=(m:=q**3)-p>>1): yield k p, q = m, nextprime(q) A360490_list = list(islice(A360490_gen(),20)) # Chai Wah Wu, Feb 27 2023
Formula
a(n) = (1/2) * A241102(n).
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