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 A356847 Greedily choose a(n) to be the least prime p > a(n-1) such that all sums a(i) + a(j) - 1, 1 <= i < j, are also prime. 0
 5, 7, 13, 67, 97, 9337, 28657, 516157, 2193637, 1725215287, 5858906527, 10845974467, 311697041437, 2748104242057, 478834469031547, 30509330585363257 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS It is not known if this sequence is infinite. LINKS Table of n, a(n) for n=1..16. Sequence inspired by (but not mentioned in) talk by Terence Tao, February 23 2023, in the Number Theory Web Seminar. PROG (Python) from math import gcd from itertools import count, islice from sympy import isprime, nextprime def agen(): # generator of terms alst = [5] while True: yield alst[-1] p = nextprime(alst[-1]) while any(not isprime(ai + p - 1) for ai in alst): p = nextprime(p) alst.append(p) print(list(islice(agen(), 9))) # Michael S. Branicky, Feb 23 2023 CROSSREFS Sequence in context: A077781 A102872 A102873 * A342506 A158892 A106022 Adjacent sequences: A356844 A356845 A356846 * A356848 A356849 A356850 KEYWORD nonn,more AUTHOR Jeffrey Shallit, Feb 23 2023 EXTENSIONS a(10)-a(12) from Michael S. Branicky, Feb 23 2023 a(13) from Rémy Sigrist, Feb 24 2023 a(14)-a(16) from Bert Dobbelaere, Mar 05 2023 STATUS approved

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Last modified March 1 22:23 EST 2024. Contains 370443 sequences. (Running on oeis4.)