A013189 - OEIS

%I #13 Apr 04 2015 02:40:34

%S 1,4,4,4,4,9,9,9,9,16,16,16,16,25,25,25,25,36,36,36,36,36,36,36,36,36,

%T 49,49,49,49,49,49,49,49,49,64,64,64,64,64,64,64,64,64,81,81,81,81,81,

%U 81,81,81,81,100,100,100,100,100,100,100,100,100,100,100,100,100,100

%N All terms are squares and a(n) is length of n-th run.

%C Golomb's sequence using squares. - _Benoit Cloitre_, Apr 20 2003

%H Ivan Neretin, <a href="/A013189/b013189.txt">Table of n, a(n) for n = 1..10000</a>

%F n-th term, divided by n, tends to square root of two.

%t f[s_] := Join@@Table[i^2, {i, Length[s]}, {s[[i]]}]; Nest[f, {1, 4}, 3]

%Y Cf. A001462, A080605, A080606, A080607.

%K nonn,easy

%O 1,2

%A _James Propp_