%I #9 Dec 26 2022 09:45:26

%S 1,3,39,15,175,63,1275,255,1215,891,495,6975,14175,26367,13311,8127,

%T 20475,42735,95931,69615,36855,24255,404415,4095,96255,423423,253935,

%U 98175,913275,165375,507375,130815,3198975,1576575,203775,2154495,4398975,1616895,1556415

%N a(n) is the least number k such that A246600(k) = n, and -1 if no such k exists.

%C All the terms are odd since A246600(2*k) = A246600(k).

%H Amiram Eldar, <a href="/A359081/b359081.txt">Table of n, a(n) for n = 1..142</a>

%H <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>.

%H <a href="/index/Di#divisors">Index entries for sequences related to divisors of numbers</a>.

%t seq[nmax_, kmax_] := Module[{s = Table[0, {nmax}], c = 0, k = 1, i}, While[c < nmax && k < kmax, i = DivisorSum[k, 1 &, BitOr[#, k] == k &]; If[i <= nmax && s[[i]] == 0, c++; s[[i]] = k]; k++]; s]; seq[20, 5*10^6]

%o (PARI) lista(nmax, kmax=oo) = {my(s = vector(nmax), c = 0, k = 1, i); while(c < nmax && k < kmax, i = sumdiv(k, d, bitor(d, k) == k); if(i <= nmax && s[i] == 0, c++; s[i] = k); k++); s};

%Y Cf. A000005, A046801, A246600, A359080, A359082, A359083.

%K nonn,base

%O 1,2

%A _Amiram Eldar_, Dec 15 2022