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A065807 Squares with a smaller square as final digits.

%I A065807 #17 Mar 17 2020 06:23:02
%S A065807 49,64,81,100,121,144,169,225,289,324,361,400,441,484,529,625,729,784,
%T A065807 841,900,961,1024,1089,1225,1369,1444,1521,1600,1681,1764,1849,1936,
%U A065807 2025,2116,2209,2304,2401,2500,2601,2704,2809,2916,3025,3136,3249,3364
%N A065807 Squares with a smaller square as final digits.
%H A065807 Vincenzo Librandi, <a href="/A065807/b065807.txt">Table of n, a(n) for n = 1..1000</a>
%t A065807 ds[n_] := NestWhileList[FromDigits[Rest[IntegerDigits[#]]] &, n, # > 9 &]; Select[Range[4, 58]^2, Or @@ IntegerQ /@ Sqrt[Rest[ds[#]]] &] (* _Jayanta Basu_, Jul 10 2013 *)
%o A065807 (PARI) a065807(m) = local(a, b, d, j, k, n); for(k=1, m, a=length(Str(n))-1; b=1; j=1; n=k^2; while(b, d=divrem(n, 10^j); if(d[1]>0&&issquare(d[2]), b=0; print1(n, ", "), if(j<a, j++, b=0))))
%o A065807 a065807(60)
%o A065807 (PARI) isokend(n) = my(p=10); for(k=1, #Str(n)-1, if (issquare(n % p), return (1)); p*=10);
%o A065807 isok(n) = issquare(n) && isokend(n); \\ _Michel Marcus_, Mar 17 2020
%Y A065807 A065808 gives the corresponding square roots.
%Y A065807 Cf. A038678.
%Y A065807 Cf. A065689, A050634, A050636, A050638, A065776, A061839, A065782, A065785, A065788, A065791.
%K A065807 nonn,base,easy
%O A065807 1,1
%A A065807 _Klaus Brockhaus_, Nov 22 2001
%E A065807 Changed offset from 0 to 1 by _Vincenzo Librandi_, Sep 24 2013