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 A168008 First differences of A168007. 3
 1, 2, -1, 3, -1, 5, -1, 3, -1, 11, -1, 3, -1, 23, -1, 3, -1, 47, -1, 3, -1, 5, -1, 3, -1, 101, -1, 3, -1, 7, -1, 11, -1, 3, -1, 13, -1, 233, -1, 3, -1, 467, -1, 3, -1, 5, -1, 3, -1, 941, -1, 3, -1, 7, -1, 1889, -1, 3, -1, 3779, -1, 3, -1, 7559, -1, 3, -1, 13, -1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Table of n, a(n) for n=1..69. PROG (Python) from itertools import count, islice from sympy import primefactors def A168008_gen(): # generator of terms a = 1 for n in count(2): yield (b:=min(primefactors(a), default=1) if a&1 or a==2 else -1) a += b A168008_list = list(islice(A168008_gen(), 20)) # Chai Wah Wu, Mar 14 2023 CROSSREFS Cf. A168007, A168009. Sequence in context: A133021 A131208 A353467 * A178810 A319627 A334990 Adjacent sequences: A168005 A168006 A168007 * A168009 A168010 A168011 KEYWORD sign AUTHOR Omar E. Pol, Nov 19 2009 EXTENSIONS More terms from Jinyuan Wang, Mar 14 2020 STATUS approved

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Last modified November 29 14:38 EST 2023. Contains 367445 sequences. (Running on oeis4.)