cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A324041 Nonpalindromic integers with palindromic product of divisors.

Original entry on oeis.org

26, 49, 2285, 1109111, 3069307, 12028229, 12866669, 110091011, 10207355549, 11010911011, 11100910111, 13579355059, 30101273647, 30693069307, 111283619361
Offset: 1

Views

Author

Michel Marcus, Sep 02 2019

Keywords

Comments

Many terms of A327325 are palindromes, hence this sequence.
Intersection of A029742 and A327325.
a(16) > 3.5*10^11. - Giovanni Resta, Sep 04 2019

Examples

			Divisors of 26 are : 1,2,13,26 and 1*2*13*26=676.

Crossrefs

Cf. A002113, A007955, A029742, A327325.

Programs

  • Mathematica
    Select[Range[3200000], !PalindromeQ[#] && PalindromeQ[#^(DivisorSigma[0, #]/2)] &] (* Amiram Eldar, Sep 02 2019 *)
  • PARI
    ispal(n) = my(d=digits(n)); d == Vecrev(d);
isok(n) = !ispal(n) && ispal(vecprod(divisors(n)));

Extensions

a(8)-a(15) from Giovanni Resta, Sep 04 2019
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Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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