%I #8 May 31 2024 22:08:09
%S 2,3,4,5,7,10,11,12,13,17,19,21,22,23,25,29,30,31,34,37,39,41,43,46,
%T 47,48,53,55,57,58,59,61,66,67,71,73,75,79,82,83,84,85,89,93,94,97,
%U 101,102,103,106,107,109,111,113,115,118,120,121,127,128,129,131,137,138,139,142,145,147,149,151,156,157,163
%N Numbers k for which A003415(k) == +1 (mod 3), where A003415 is the arithmetic derivative.
%H Antti Karttunen, <a href="/A373255/b373255.txt">Table of n, a(n) for n = 1..10000</a>
%o (PARI) isA373255 = A373254;
%Y Positions of +1's in A373253.
%Y Cf. A000040 (subsequence), A003415, A373254 (characteristic function).
%K nonn
%O 1,1
%A _Antti Karttunen_, May 31 2024