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

Author

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

Keywords

• nonn
• base

Comments

A conjugate sequence to A230495 and A230496.

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

Crossrefs

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

Programs

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 *)

Extensions

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