A230496 - OEIS

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.

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

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OFFSET

1,1

COMMENTS

Conjecture: for all n, a(n) > 0.

LINKS

Table of n, a(n) for n=1..33.

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

Cf. A000069, A001969, A230454, A230495.

Sequence in context: A363153 A247666 A255279 * A295733 A341201 A255277

Adjacent sequences: A230493 A230494 A230495 * A230497 A230498 A230499

KEYWORD

nonn,base

AUTHOR

Vladimir Shevelev and Peter J. C. Moses, Oct 21 2013

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