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 A034822 Numbers n such that there are no palindromic squares of length n. 11
 2, 4, 8, 10, 14, 18, 20, 24, 30, 38, 40 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Table of n, a(n) for n=1..11. Patrick De Geest, Palindromic Squares Eric Weisstein's World of Mathematics, Palindromic Number MATHEMATICA A034822[n_] := Select[Range[Ceiling[Sqrt[10^(n - 1)]], Floor[Sqrt[10^n]]], #^2 == IntegerReverse[#^2] &]; Select[Range[12], Length[A034822[#]] == 0 &] (* Robert Price, Apr 23 2019 *) PROG (Python) from sympy import integer_nthroot as iroot def ispal(n): s = str(n); return s == s[::-1] def ok(n): for r in range(iroot(10**(n-1), 2)[0] + 1, iroot(10**n, 2)[0]): if ispal(r*r): return False return True print([m for m in range(1, 16) if ok(m)]) # Michael S. Branicky, Feb 04 2021 CROSSREFS Cf. A002778, A002779, A034307. Sequence in context: A189670 A341822 A363797 * A300781 A050567 A069879 Adjacent sequences: A034819 A034820 A034821 * A034823 A034824 A034825 KEYWORD nonn,base,hard,more AUTHOR Patrick De Geest, Oct 15 1998 EXTENSIONS Two more terms from Patrick De Geest, Apr 01 2002 STATUS approved

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Last modified December 4 10:17 EST 2023. Contains 367560 sequences. (Running on oeis4.)