%I #9 May 07 2019 23:13:43
%S 0,5,9,14,19,23,28,31,36,40,45,49,54,57,62,66,71,76,80,85,88,93,97,
%T 102,107,111,116,119,124,128,133,137,142,145,150,154,159,164,168,173,
%U 176,181,185,190,193,198,202,207,212,216,221,224,229,233,238,242,247,250,255,259,264,269,273,278
%N Indices of 1's in A305389.
%H Robert Israel, <a href="/A316324/b316324.txt">Table of n, a(n) for n = 1..10000</a>
%p f:= 'f':
%p f(1):= 2: f(2):= 3: f(3):= (1,2,3):
%p S:= [1];
%p for i from 1 to 5 do T:= map(f,S); U:= map(f,T); S:= map(f,U); od:
%p select(t -> S[t+1]=1, [$0..nops(S)-1]); # _Robert Israel_, May 07 2019
%Y Cf. A305389.
%Y A316324, A316325, A316326 have the same relation to A305389 as A003144, A003145, A003146 do to the ternary tribonacci word A080843 (or A092782).
%K nonn
%O 1,2
%A _N. J. A. Sloane_, Jul 09 2018