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 A328177 a(n) is the minimal value of the expression d OR (n/d) where d runs through the divisors of n and OR denotes the bitwise OR operator. 3
 1, 3, 3, 2, 5, 3, 7, 6, 3, 7, 11, 6, 13, 7, 7, 4, 17, 7, 19, 5, 7, 11, 23, 6, 5, 15, 11, 7, 29, 7, 31, 12, 11, 19, 7, 6, 37, 19, 15, 13, 41, 7, 43, 15, 13, 23, 47, 12, 7, 15, 19, 13, 53, 15, 15, 14, 19, 31, 59, 13, 61, 31, 15, 8, 13, 15, 67, 21, 23, 15, 71, 9 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Rémy Sigrist, Table of n, a(n) for n = 1..16384 Rémy Sigrist, Logarithmic scatterplot of the first 2^16 terms FORMULA a(n)^2 >= n with equality iff n is a square. a(p) = p for any odd prime number p. EXAMPLE For n = 12: - we have the following values: d 12/d d OR (12/d) -- ---- ----------- 1 12 13 2 6 6 3 4 7 4 3 7 6 2 6 12 1 13 - hence a(12) = min({6, 7, 13}) = 6. MAPLE a:= n-> min(map(d-> Bits[Or](d, n/d), numtheory[divisors](n))): seq(a(n), n=1..100); # Alois P. Heinz, Oct 09 2019 PROG (PARI) a(n) = vecmin(apply(d -> bitor(d, n/d), divisors(n))) CROSSREFS See A328176 and A328178 for similar sequences. Cf. A218388. Sequence in context: A110897 A116644 A166462 * A320776 A279056 A265751 Adjacent sequences: A328174 A328175 A328176 * A328178 A328179 A328180 KEYWORD nonn,base AUTHOR Rémy Sigrist, Oct 06 2019 STATUS approved

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Last modified September 26 11:55 EDT 2023. Contains 365656 sequences. (Running on oeis4.)