A196872 - OEIS

%I #8 Jul 30 2021 15:06:36

%S 1,2,2,6,6,6,6,6,6,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,

%T 42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,

%U 42,42,1806,1806,1806,1806,1806,1806,1806,1806,1806,1806,1806,1806,1806,1806,1806,1806,1806

%N A007018(n) repeated A007018(n) times.

%C Sequence of integers k_n in which k_n appears k_n times and k_n =1+((k_0)^2+(k_1)^2+...+(k_(n-1))^2).

%e k_0=1,and k_1=1+1=2 ;

%e 1,2,2, and k_2=1+(1+2+2)=1+5=6 ;

%e 1,2,2,6,6,6,6,6,6, and k_3=1+(1+2+2+6+6+6+6+6+6)=1+41=42 ;

%e 1,2,2,6,6,6,6,6,6,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,42,and k_4=1+(1+2+2+...+42)=1+1805=1806 ; etc.

%t Table[#,#]&/@NestList[#^2+#&,1,4] //Flatten (* _Harvey P. Dale_, Jul 30 2021 *)

%Y A007018

%K nonn,easy

%O 0,2

%A _Philippe Deléham_, Oct 06 2011