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A230496
a(n) is the minimal odd odious k > 1, such that k^i, i=1,2,...,n, all are odious, or a(n)=0, if there is no such k.
4
7, 7, 25, 59, 103, 103, 103, 103, 1305, 1305, 10525, 10525, 10525, 25127, 25127, 25127, 106501, 215735, 810163, 810163, 810163, 9554677, 13101403, 13101403, 14299679, 37795511, 37795511, 37795511, 3197105709, 3197105709, 5386711727, 14904706741, 20696039773
OFFSET
1,1
COMMENTS
Conjecture: for all n, a(n) > 0.
LINKS
Vladimir Shevelev, "Odious-evil stability" of integers, post to the SeqFan Mailing List, Oct 20 2013.
MATHEMATICA
odQ[n_] := OddQ[DigitCount[n, 2, 1]]; odExp[n_] := Module[{e = 1, p = n}, If[odQ[n], While[odQ[p], p *= n; e++]]; e]; seq[nmax_] := Module[{e, emax = 1, n = 3, s = {}}, Do[e = odExp[n]; If[e > emax, s = Join[s, ConstantArray[n, e - emax]]; emax = e], {n, 3, nmax, 2}]; s]; seq[26000] (* Amiram Eldar, Aug 03 2023 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
EXTENSIONS
a(17)-a(22) from Alois P. Heinz, Oct 21 2013
a(23)-a(27) from Peter J. C. Moses, Oct 22 2013
a(28)-a(33) from Amiram Eldar, Aug 03 2023
STATUS
approved