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%I #18 Feb 20 2023 14:50:25
%S 1,16,100,1024,10000,100489,1000000,10004569,100000000,1000014129,
%T 10000000000,100000147984,1000000000000,10000002149284,
%U 100000000000000,1000000025191729,10000000000000000,100000000621806289,1000000000000000000,10000000005259630921
%N a(n) = smallest n-digit square.
%H Robert Israel, <a href="/A061432/b061432.txt">Table of n, a(n) for n = 1..999</a>
%F a(n) = ceiling(10^((n-1)/2))^2. - Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 30 2003
%e a(4) = 1024 = 32^2 has 4 digits while 31^2 = 961 has 3 digits.
%p A061432 := n->ceil(10^((n-1)/2))^2;
%t Table[Ceiling[Sqrt[10^n]]^2,{n,0,20}] (* _Harvey P. Dale_, Dec 29 2015 *)
%o (PARI) {a(n) = ceil(sqrt(10^n))^2}; \\ _G. C. Greubel_, Mar 08 2019
%o (Magma) [Ceiling(Sqrt(10^n))^2: n in [0..20]]; // _G. C. Greubel_, Mar 08 2019
%o (Sage) [ceil(sqrt(10^n))^2 for n in (0..20)] # _G. C. Greubel_, Mar 08 2019
%o (Python)
%o from math import isqrt
%o def A061432(n): return (isqrt(10**(n-1)-1)+1)**2 # _Chai Wah Wu_, Feb 20 2023
%Y Cf. A065736.
%K nonn,base,easy
%O 1,2
%A _Amarnath Murthy_, May 03 2001
%E More terms from Larry Reeves (larryr(AT)acm.org), May 16 2001
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