A316326 - OEIS

A316326

Indices of 3's in A305389.

2, 4, 7, 8, 11, 13, 16, 18, 21, 22, 25, 27, 30, 33, 35, 38, 39, 42, 44, 47, 48, 51, 53, 56, 59, 61, 64, 65, 68, 70, 73, 75, 78, 79, 82, 84, 87, 90, 92, 95, 96, 99, 101, 104, 106, 109, 110, 113, 115, 118, 121, 123, 126, 127, 130, 132, 135, 136, 139, 141, 144, 147, 149, 152, 153, 156, 158, 161, 163, 166, 167, 170, 172

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

MAPLE

f:= 'f':

f(1):= 2: f(2):= 3: f(3):= (1, 2, 3):

S:= [1];

for i from 1 to 5 do T:= map(f, S); U:= map(f, T); S:= map(f, U); od:

select(t -> S[t+1]=3, [$0..nops(S)-1]); # Robert Israel, May 07 2019

CROSSREFS