A362284 a(n) is the least number k such that A138705(k) = n, or -1 if no such k exists.

0, 1, 5, 10, 23, 6, 8, 20, 50, 18, 69, 66, 100, 45, 56, 42, 30, 40, 96, 99, 72, 234, 36, 348, 156, 200, 168, 120, 405, 390, 216, 315, 90, 198, 280, 270, 792, 210, 180, 624, 1120, 360, 576, 1188, 1134, 420, 750, 1140, 504, 1728, 660, 600, 690, 540, 630, 1380, 810

Offset: 1

Author

Amiram Eldar, Apr 14 2023

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..168

Crossrefs

Cf. A000367, A002445, A027641, A027642, A138705, A362285, A362286.

Programs

Mathematica

seq[len_, nmax_] := Module[{s = Table[-1, {len}], c = 0, n = 0, i}, While[c < len && n <= nmax, i = Length[ContinuedFraction[Abs[BernoulliB[2*n]]]]; If[i <= len && s[[i]] < 0, c++; s[[i]] = n]; n++]; s]; seq[60, 10^4]

PARI

lista(len, nmax) = {my(s = vector(len,i,-1), c = 0, n = 0, i); while(c < len && n <= nmax, i = #contfrac(abs(bernfrac(2*n))); if(i <= len && s[i] < 0, c++; s[i] = n); n++); s;}