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a(n) = floor( {n concatenated with n n times }^(1/2) * 10 )^2.
0

%I #14 Nov 13 2024 16:40:21

%S 100,2116,33124,443556,5555449,66650896,777740544,8888718400,

%T 99999515529,1010101010089161070864,111111111110888888888889,

%U 12121212121205459165906769,1313131313131245483985582729,141414141414141058690681961329,15151515151515144862248400372996

%N a(n) = floor( {n concatenated with n n times }^(1/2) * 10 )^2.

%F Floor[ {n concatenated with n n times }^(1/2)*10]^2 - Michael Keagel (mjk374(AT)psu.edu), Feb 12 2006

%e a(3) = floor(333^(1/2)*10)^2 = 33124.

%p a:= n-> floor(sqrt(parse(cat(n$n)))*10)^2:

%p seq(a(n), n=1..15); # _Alois P. Heinz_, Nov 13 2024

%t Table[Floor[10 *Surd[FromDigits[Flatten[IntegerDigits/@ PadRight[ {}, n, n]]], 2]]^2, {n, 15}] (* _Georg Fischer_, Nov 13 2024 *)

%Y Cf. A114776.

%K base,nonn

%O 1,1

%A _Amarnath Murthy_, Nov 17 2005

%E Corrected and extended by Michael Keagel (mjk374(AT)psu.edu), Feb 12 2006

%E Offset changed to 1; a(12) corrected and more terms from _Georg Fischer_, Nov 13 2024