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 A234962 Primes missing from the tree generated at A234960. 3
 71, 101, 109, 151, 181, 191, 229, 233, 239, 241, 269, 283, 311, 349, 367, 373, 379, 409, 419, 433, 439, 461, 463, 467, 479, 487, 491, 569, 571, 593, 599, 601, 607, 643, 647, 653, 659, 683, 727, 733, 739, 743, 751, 757, 811, 821, 823, 827, 829, 857, 877, 881 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS According to the conjecture at A234961, the limiting relative density of these primes is 1. LINKS Clark Kimberling, Table of n, a(n) for n = 1..7000 MATHEMATICA t = NestList[DeleteDuplicates[Flatten[Map[{#, NextPrime[2 #, -1], NextPrime[2 #, 1]} &, #]]] &, {2}, 12]; Complement[Map[Prime, Range[PrimePi[Last[#]]]], #] &[Last[t]] (* Peter J. C. Moses, Dec 30 2013 *) PROG (Python) from sympy import prevprime, nextprime, primerange def aupto(limit): reach, expand = {2}, [2] while True: newreach = set() while len(expand) > 0: p = expand.pop() for q in prevprime(2*p), nextprime(2*p): if q not in reach: newreach.add(q) reach |= newreach expand = list(newreach) if prevprime(2*min(expand)) > limit: in_tree = set(r for r in reach if r <= limit) return sorted(set(primerange(1, limit+1)) - in_tree) print(aupto(881)) # Michael S. Branicky, Jul 24 2022 CROSSREFS Cf. A234960, A234961. Sequence in context: A155953 A247200 A288907 * A166252 A339466 A339463 Adjacent sequences: A234959 A234960 A234961 * A234963 A234964 A234965 KEYWORD nonn AUTHOR Clark Kimberling, Jan 01 2014 STATUS approved

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Last modified June 25 10:55 EDT 2024. Contains 373701 sequences. (Running on oeis4.)