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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
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
Sequence in context: A034028 A268272 A102700 * A047481 A372325 A158704
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.)