A038678 Squares ending in a different nonzero square.

49, 64, 81, 121, 144, 169, 225, 289, 324, 361, 441, 484, 529, 625, 729, 784, 841, 961, 1024, 1089, 1225, 1369, 1444, 1521, 1681, 1764, 1849, 1936, 2025, 2116, 2209, 2304, 2401, 2601, 2704, 2809, 2916, 3025, 3136, 3249, 3364, 3481, 3721, 3844, 3969, 4225

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• base
• easy

Comments

Subsequence of A065807. - Zak Seidov, Mar 23 2012

Examples

			15^2 = 225 ends with 25 = 5^2.
		

Links

• Jinyuan Wang, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A000290, A065807.

Programs

Maple

q:= n-> (s-> ormap(x-> (t-> t>0 and issqr(t))(parse(x))
             , [s[i..-1]$i=2..length(s)]))(""||n):
select(q, [i^2$i=1..100])[];  # Alois P. Heinz, Mar 16 2020

Mathematica

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 *)

PARI

issqend(n) = my(p=10, q); for(k=1, #Str(n)-1, if ((q=(n % p)) && issquare(q), return (1)); p*=10);
isok(n) = issquare(n) && issqend(n); \\ Michel Marcus, Mar 17 2020