A082026 - OEIS

%I #9 Jan 10 2025 04:32:08

%S 5,25,425,16425,13616425,193613616425,181936193613616425,

%T 164181936181936193613616425,

%U 13616164181936164181936181936193613616425,19361361361616418193613616164181936164181936181936193613616425

%N a(1)=5; a(n) is concatenation of squares of digits in a(n-1) (in base 10).

%C If m is a member of the sequence represented by k digits in base 10, all members greater than m are congruent to m mod 10^k.

%H Paolo Xausa, <a href="/A082026/b082026.txt">Table of n, a(n) for n = 1..16</a>

%e The squares of the digits in the third term, 425, are 16, 4 and 25; hence a(4)=16425.

%t NestList[FromDigits[Flatten[IntegerDigits[IntegerDigits[#]^2]]] &, 5, 10] (* _Paolo Xausa_, Jan 10 2025 *)

%Y Cf. A061588.

%K base,easy,nonn

%O 1,1

%A _Matthew Vandermast_, Apr 01 2003