OFFSET
1,1
LINKS
Michael S. Branicky, Table of n, a(n) for n = 1..425 (all terms < 10^11; terms 1..68 from Bui Quang Tuan)
EXAMPLE
The nonpalindromic number 5265 is a term because abs(5265^2 - 5625^2) = 1980^2.
MATHEMATICA
Select[Range[200000], ! PalindromeQ@ # && IntegerQ@ Sqrt@ Abs[#^2 - IntegerReverse[#]^2] &] (* Michael De Vlieger, Mar 02 2022 *)
PROG
(Magma) [n: n in [0..10^6] | Intseq(n) ne Reverse(Intseq(n)) and IsSquare(s) where s is Abs(n^2-Seqint(Reverse(Intseq(n)))^2)]; // Bruno Berselli, Apr 01 2015
(Python)
from sympy.ntheory.primetest import is_square
def R(n): return int(str(n)[::-1])
def ok(n): Rn = R(n); return n != Rn and is_square(abs(n**2 - Rn**2))
print([k for k in range(10**6) if ok(k)]) # Michael S. Branicky, Mar 02 2022
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Bui Quang Tuan, Apr 01 2015
STATUS
approved