A230497 a(n), n>=2, is the minimal odd evil k, such that k^i, i=2,3,...,n, all are odious, and a(n)=0, if there is no such k.

5, 23, 71, 85, 89, 163, 225, 225, 225, 225, 6075, 6075, 9859, 9859, 9859, 9859, 9859, 9859, 5031037, 10430265, 11896187, 11896187, 11896187, 22402429, 340713205, 570919625, 570919625, 570919625, 1496195709, 1496195709, 1496195709, 5743845611, 8271306199, 8271306199, 8271306199

Offset

2,1

Comments

A conjugate sequence to A230495 and A230496.

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

Links

Table of n, a(n) for n=2..36.

Mathematica

odQ[n_] := OddQ[DigitCount[n, 2, 1]]; odExp[n_] := Module[{e = 1, p = n^2}, 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[10000] (* Amiram Eldar, Aug 03 2023 *)

Crossrefs

Cf. A000069, A001969, A230454, A230495, A230496.

Sequence in context: A395112 A243442 A064395 * A138905 A125955 A103478

Adjacent sequences: A230494 A230495 A230496 * A230498 A230499 A230500

Keyword

nonn,base

Author

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

Extensions

a(26)-a(36) from Amiram Eldar, Aug 03 2023

Status

approved