%I #14 Mar 08 2017 09:09:09
%S 285290,37501930,5986235584,6402200716,7097946940,2189113296470,
%T 533822715205534,120542200191255266,175167560462651234,
%U 1035777761966641262300,55811056504696202088334,87383897508158263975600,342433449090893699643070,356558269841736892522930
%N Numbers whose squares remain squares when prepended with 1 and appended with 25 in base 10.
%C Square roots of A249621.
%C a(34) >= 10^50. - _Hiroaki Yamanouchi_, Nov 22 2014
%C a(34) = 3894512793630238968387948459831502376753914222969510. - _Giovanni Resta_, Mar 08 2017
%H Chai Wah Wu and Hiroaki Yamanouchi, <a href="/A249633/b249633.txt">Table of n, a(n) for n = 1..33</a> (terms a(1)-a(27) from Chai Wah Wu)
%e 81390384100 = 285290^2 and 18139038410025 = 4258995^2.
%t a249633Q[n_Integer] :=
%t Module[{m, t}, m := ToString[n^2];
%t IntegerQ[Sqrt[ToExpression["1" <> m <> "25"]]]]; Select[Range[300000], a249633Q[#] &] (* _Michael De Vlieger_, Nov 06 2014 *)
%Y Cf. A249621.
%K nonn,base
%O 1,1
%A _Chai Wah Wu_, Nov 02 2014
|