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 A095371 Number of distinct prime factors of record setting repunits (A328899). 5
 0, 1, 2, 5, 7, 8, 10, 13, 14, 20, 21, 22, 26, 29, 32, 33, 34, 35, 40, 44, 55, 56, 63 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Conjecture: a(24) = 73, a(25) = 94, a(26) = 99, a(27) >= 107, a(28) >= 127, a(29) >= 136, a(30) >= 140, a(31) >= 151, a(32) >= 159, a(33) >= 163, a(34) >= 178, a(35) >= 184, a(36) >= 213, a(37) >= 214. - Chai Wah Wu, Nov 01 2019 LINKS Table of n, a(n) for n=1..23. MATHEMATICA r[n_] := (10^n-1)/9; L = {}; bst = -1; Do[v = PrimeNu[r[n]]; If[v > bst, bst = v; AppendTo[L, v]], {n, 60}]; L (* or, based on the b-file of A095370: *) w = Last /@ Cases[Import["https://oeis.org/A095370/b095370.txt", "Table"], {_Integer, _Integer}]; L = {}; bst = -1; Do[ If[j > bst, AppendTo[L, bst = j]], {j, w}]; L (* Giovanni Resta, Oct 30 2019 *) CROSSREFS Cf. A067063, A003020, A001221, A002275, A095370, A004023. Sequence in context: A034028 A268272 A102700 * A047481 A372325 A158704 Adjacent sequences: A095368 A095369 A095370 * A095372 A095373 A095374 KEYWORD nonn,more,base,hard AUTHOR Labos Elemer, Jun 04 2004 EXTENSIONS Data corrected by Ray Chandler and N. J. A. Sloane, May 03 2017 Name edited by Giovanni Resta, Oct 30 2019 a(20)-a(21) from Chai Wah Wu, Oct 30 2019 a(22)-a(23) from Chai Wah Wu, Nov 01 2019 STATUS approved

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