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A275493
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Number of primitive weird numbers (A002975) below 2^n.
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3
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0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 3, 6, 8, 9, 10, 14, 16, 20, 24, 29, 33, 46, 55, 61, 79, 87, 103, 128, 152, 173, 234, 266, 313, 403, 483, 561, 756, 850, 940
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OFFSET
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0,11
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COMMENTS
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It is not known unconditionally whether there are infinitely many primitive weird numbers (PWN, A002975), although numerical data provides strong evidence: even the number of weird numbers of the form 2^k*p*q (A258882, A258333) seems to increase rapidly as k increases. Melfi has shown that Cramer's conjecture implies the infiniteness of PWN.
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LINKS
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PROG
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(PARI) vector(40, n, #select(t->t<2^n, A002975)) \\ assuming that A002975 is defined as a set, vector or list with enough terms.
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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a(0) inserted, a(39) corrected, and a(40) added by Amiram Eldar, Sep 02 2023
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STATUS
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approved
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