|
%I #8 Aug 12 2018 16:13:10
%S 16,25,36,49,529,64,729,81,900,1156,225,3364,441,55225,66049,7744,
%T 8836,99225,101124,111556,12100,131044,14161,15129,16129,17161,181476,
%U 191844,2025,212521,22201,232324,242064,25281,26244,27225
%N Smallest nontrivial extension of n-th palindrome which is a square.
%H Robert Israel, <a href="/A030676/b030676.txt">Table of n, a(n) for n = 1..10000</a>
%p revdigs:= proc(n)
%p local L, nL, i;
%p L:= convert(n, base, 10);
%p add(L[-i]*10^(i-1), i=1..nops(L));
%p end:
%p g:= proc(d) local m,x,y;
%p if d::even then
%p m:= d/2;
%p seq(x*10^m+revdigs(x),x=10^(m-1)..10^m-1)
%p else
%p m:= (d-1)/2;
%p seq(seq(x*10^(m+1)+y*10^m+revdigs(x),y=0..9),x=10^(m-1)..10^m-1)
%p fi
%p end proc:
%p g(1):= $1..9:
%p f:= proc(x) local d,y;
%p for d from 1 do
%p y:= ceil(sqrt(x*10^d))^2;
%p if y < (x+1)*10^d then return y fi
%p od;
%p end proc:
%p map(f, [g(1),g(2),g(3)]); # _Robert Israel_, Aug 12 2018
%Y Cf. A030677.
%K nonn,base,look
%O 1,1
%A _Patrick De Geest_
|
