A374221 - OEIS

%I #10 Jul 09 2024 19:33:52

%S 3,4,5,12,15,20,21,24,33,35,36,39,40,44,45,48,51,52,55,57,60,65,68,69,

%T 75,76,80,85,87,92,93,95,96,100,105,108,111,115,116,120,123,124,129,

%U 132,135,141,145,147,148,155,156,159,160,164,165,168,172,177,180,183,185,188,189,192,195,196,201,204,205,212,213

%N Indices of 1's in A374200, where A374200 is the minimum value of A347381 that it obtains among unitary divisors of n larger than 1.

%C It seems that for all odd terms x in this sequence, A374204(x) = 1, and they form a subsequence of all terms k for which A374204(k) = 1, that might be sequence A086748.

%H Antti Karttunen, <a href="/A374221/b374221.txt">Table of n, a(n) for n = 1..20001</a>

%o (PARI) isA374221 = A374220;

%Y Cf. A000203, A005940, A347381, A374200, A374204, A374220 (characteristic function).

%Y Cf. also A086748 and A347391 (very likely a subsequence).

%K nonn

%O 1,1

%A _Antti Karttunen_, Jul 09 2024