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A034978 a(n)^2 is smallest square starting with a string of n 1's. 3

%I #11 May 31 2023 11:21:24

%S 1,34,334,3334,10541,333334,3333334,33333334,333333334,3333333334,

%T 10540925534,105409255339,3333333333334,10540925533895,

%U 105409255338946,105409255338946,10540925533894598,105409255338945978,3333333333333333334,33333333333333333334,333333333333333333334,1054092553389459777333

%N a(n)^2 is smallest square starting with a string of n 1's.

%H Robert Israel, <a href="/A034978/b034978.txt">Table of n, a(n) for n = 1..996</a>

%F a(n) <= A093137(n). - _Robert Israel_, May 31 2023

%e a(5)^2 = 10541^2 = {11111}2681.

%p f:= proc(n) local x, k, s;

%p x:= (10^n-1)/9;

%p for k from 0 do

%p s:= ceil(sqrt(10^k*x));

%p if s^2 < (x+1)*10^k then return s fi

%p od

%p end proc:

%p map(f, [$1..20]); # _Robert Israel_, May 31 2023

%Y Cf. A034979, A093137.

%K nonn,base

%O 1,2

%A _Patrick De Geest_, Nov 15 1998

%E More terms from Francisco Salinas (franciscodesalinas(AT)hotmail.com), Dec 23 2001

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Last modified April 18 20:26 EDT 2024. Contains 371781 sequences. (Running on oeis4.)