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Metadata 
bibkey: brockhaus2007a133901
authors: Klaus Brockhaus; Zak Seidov
year: 2007
title: "OEIS A133901, Numbers in A128921 whose square is not a palindrome"
doi: null
url: https://oeis.org/A133901
claim: "A133901 %N: Numbers in A128921 whose square is not a palindrome. A128921 %N: Palindromes m such that reverse of m^2 is also a square. A133901 %C: Conjecture: Sequence is infinite. A133901 %e: A128921(41) = 1119111, 1119111^2 = 1252409430321 is not a palindrome, but its reverse is also a square: 1230349042521 = 1109211^2. A133901 %A: _Klaus Brockhaus_ and _Zak Seidov_, Sep 29 2007"
strata_touched:
  - D5/S1/Digit/Admissibility/PalindromeSquareReversalInfinitude
license: citation-only
triage: anchor

OEIS A133901

The entry selects from A128921 the decimal palindromes whose squares are not palindromes. A128921 requires the reversed decimal representation of the square to have a perfect-square numeric value.

The formal module proves that these selected palindromes are unbounded, which is equivalent to infinitude over the natural numbers. It makes no density or enumeration claim.

Verified locator

  • URL: https://oeis.org/A133901
  • Locator: COMMENT, “Conjecture: Sequence is infinite.”