|
%I #22 Mar 17 2020 14:45:07
%S 49,64,81,121,144,169,225,289,324,361,441,484,529,625,729,784,841,961,
%T 1024,1089,1225,1369,1444,1521,1681,1764,1849,1936,2025,2116,2209,
%U 2304,2401,2601,2704,2809,2916,3025,3136,3249,3364,3481,3721,3844,3969,4225
%N Squares ending in a different nonzero square.
%C Subsequence of A065807. - _Zak Seidov_, Mar 23 2012
%H Jinyuan Wang, <a href="/A038678/b038678.txt">Table of n, a(n) for n = 1..1000</a>
%e 15^2 = 225 ends with 25 = 5^2.
%p q:= n-> (s-> ormap(x-> (t-> t>0 and issqr(t))(parse(x))
%p , [s[i..-1]$i=2..length(s)]))(""||n):
%p select(q, [i^2$i=1..100])[]; # _Alois P. Heinz_, Mar 16 2020
%t ds[n_] := DeleteCases[NestWhileList[FromDigits[Rest[IntegerDigits[#]]] &, n, # > 9 &], 0]; Select[Range[4, 65]^2, Or @@ IntegerQ /@ Sqrt[Rest[ds[#]]] &] (* _Jayanta Basu_, Jul 10 2013 *)
%o (PARI) issqend(n) = my(p=10, q); for(k=1, #Str(n)-1, if ((q=(n % p)) && issquare(q), return (1)); p*=10);
%o isok(n) = issquare(n) && issqend(n); \\ _Michel Marcus_, Mar 17 2020
%Y Cf. A000290, A065807.
%K nonn,base,easy
%O 1,1
%A _N. J. A. Sloane_
|
