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 A028570 Numbers n such that n(n + 9) is a palindrome. 0
 0, 2, 12, 44, 137, 157, 167, 248, 258, 1639, 1664, 1694, 5392, 15904, 16997, 160187, 487619, 1547147, 14674184, 14790532, 15019614, 15336644, 25234083, 26132578, 26211438, 26216753 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Patrick De Geest, Palindromic Quasipronics of the form n(n+x) Erich Friedman, What's Special About This Number? (See entries 258, 1664.) MATHEMATICA Select[Range[0, 9999], PalindromeQ[#^2 + 9#] &] (* Alonso del Arte, Nov 10 2019 *) PROG (Scala) def palQ(n: Int, b: Int = 10): Boolean = n - Integer.parseInt(n.toString.reverse) == 0 (0 to 9999).filter((n: Int) => palQ(n * n + 9 * n)) // Alonso del Arte, Nov 10 2019 (MAGMA) f:=func; [k:k in [0..2*10^7]| f(k*(k+9))]; // Marius A. Burtea, Nov 11 2019 CROSSREFS Cf. A028569, A028571. Sequence in context: A203278 A013704 A025495 * A009074 A267344 A275132 Adjacent sequences:  A028567 A028568 A028569 * A028571 A028572 A028573 KEYWORD nonn,base,easy AUTHOR STATUS approved

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Last modified April 12 18:58 EDT 2021. Contains 342932 sequences. (Running on oeis4.)