A065807 -id:A065807 - cp's OEIS frontend

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

N. J. A. Sloane

Subsequence of A065807. - Zak Seidov, Mar 23 2012

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

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

Cf. A000290, A065807.

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

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 *)

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

A065808 Square of n has a smaller square as its final digits.

Original entry on oeis.org

7, 8, 9, 10, 11, 12, 13, 15, 17, 18, 19, 20, 21, 22, 23, 25, 27, 28, 29, 30, 31, 32, 33, 35, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 65, 67, 68, 69, 70, 71, 72, 73, 75, 77, 78, 79, 80, 81, 82, 83, 85, 87, 88

Offset: 1

Klaus Brockhaus, Nov 22 2001

Includes all n >= 7 not == 4 or 6 (mod 10). - Robert Israel, Oct 24 2017

Robert Israel, Table of n, a(n) for n = 1..10000

A065807 gives the corresponding squares.

Cf. A065690, A050635, A050637, A050639, A065777, A065780, A065783, A065786, A065789, A065792.

filter:= n ->
  ormap(t -> issqr(n^2 mod 10^t), [$1..ilog10(n^2)]):
select(filter, [$1..100]); # Robert Israel, Oct 24 2017

ds[n_] := NestWhileList[FromDigits[Rest[IntegerDigits[#]]] &, n, # > 9 &]; Select[Range[4, 88], Or @@ IntegerQ /@ Sqrt[Rest[ds[#^2]]] &] (* Jayanta Basu, Jul 10 2013 *)

a065808(m) = local(k, a, b, d, j, n, r); 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; issquare(n, &r); print1(r, ","), if(j

Offset changed to 1 by Robert Israel, Oct 24 2017

cp's OEIS Frontend

A038678 Squares ending in a different nonzero square.

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