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 A342591 Numbers k such that A340740(k) <= k. 0
 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 24, 25, 26, 28, 30, 32, 33, 34, 36, 40, 42, 46, 48, 54, 60, 78 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Numbers k such that Sum_{1<=j<=k/2, j and k coprime} (k-j mod j) <= k. Conjecture: these are all the terms. The terms with A340740(k) = k are 19 and 48. LINKS Table of n, a(n) for n=1..38. EXAMPLE a(7) = 7 is a term because A340740(7) = 2 <= 7. MAPLE f:= proc(n) local k; add(`if`(igcd(k, n)=1, n mod k, 0), k=1..floor(n/2)) end proc: select(t -> f(t) <= t, [\$1..1000]); CROSSREFS Cf. A340740 Sequence in context: A080682 A182049 A038770 * A193176 A263314 A267086 Adjacent sequences: A342588 A342589 A342590 * A342592 A342593 A342594 KEYWORD nonn,more AUTHOR J. M. Bergot and Robert Israel, Mar 16 2021 STATUS approved

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Last modified September 29 13:36 EDT 2023. Contains 365771 sequences. (Running on oeis4.)