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Smallest extension of n-th prime which is a square.
2

%I #11 Sep 06 2016 03:13:59

%S 25,36,529,729,1156,1369,1764,196,2304,2916,3136,3721,41209,4356,4761,

%T 5329,5929,61009,676,71289,7396,7921,83521,89401,97344,101124,103041,

%U 107584,109561,113569,12769,131044,137641,13924,149769,15129

%N Smallest extension of n-th prime which is a square.

%H Robert Israel, <a href="/A030671/b030671.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A030666(A000040(n)). - _Robert Israel_, Sep 05 2016

%e For n=2, the second prime is 3, and 36 is the smallest square that begins with 3, so a(2) = 36. - _Michael B. Porter_, Sep 06 2016

%p A030666:= proc(x) local d;

%p for d from 1 do

%p if ceil(sqrt(10^d*x)) <= floor(sqrt(10^d*(x+1)-1)) then

%p return ceil(sqrt(10^d*x))^2

%p fi

%p od

%p end proc:

%p seq(A030666(ithprime(i)),i=1..100); # _Robert Israel_, Sep 05 2016

%Y Cf. A000040, A030666, A030672.

%K nonn,base

%O 1,1

%A _Patrick De Geest_

%E Name edited by _Robert Israel_, Sep 06 2016