|
%I #14 Jun 10 2019 10:22:19
%S 1,25,361,4900,59536,698896,7997584,89984196,999950884,1099983556,
%T 11999887936,129999908025,1399997736225,14999997318289,
%U 159999983792100,1699999978875136,17999999825590084,189999999691331236,1999999998944727844,20999999991239581636,219999999994324356676,2299999999987799844289
%N Largest n-digit square beginning with n.
%F a(n) = (ceiling(sqrt((n+1)*10^(n-floor(log_10(10*n))))) - 1)^2 = (ceiling(sqrt((n+1)*10^(n-A055642(n)))) - 1)^2. - Antonio G. Astudillo (afg_astudillo(AT)hotmail.com), Nov 16 2002
%t f[n_] := Module[{idn=IntegerDigits[n]}, FromDigits[Join[idn, Table[9, {n-Length[idn]}]]]]; Table[Floor[Sqrt[f[i]]]^2, {i, 30}]
%o (PARI) a(n) = if(n==1,return(1));my(d=digits(n+1));d=concat(d,vector(n-#digits(n))); floor(sqrt(fromdigits(d)-1))^2 \\ _David A. Corneth_, Jun 08 2019
%K base,nonn
%O 1,2
%A _Amarnath Murthy_, Nov 08 2002
%E More terms from _Harvey P. Dale_ and Antonio G. Astudillo (afg_astudillo(AT)hotmail.com), Nov 14 2002
%E a(1) prepended and more terms from _David A. Corneth_, Jun 08 2019
|
