A324041 Nonpalindromic integers with palindromic product of divisors.

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

Offset

1,1

Comments

Many terms of A327325 are palindromes, hence this sequence.

a(16) > 3.5*10^11. - Giovanni Resta, Sep 04 2019

Number m is a term iff m^(A000005(m)/2) is in A075786. The sequence likely continues with 1100009100011, 1110009100111, 110010091010011, 111000091000111, 3107974295870663, 3138199296186067, 10010099900101001, 10100009901000101, 11100000910000111, 13593470459544309, 306950094269977057, 1000109999000110001, 1000110009100110001, 1000110099010110001, 1100000009100000011, 100010099990001010001, 100100109990011001001, 101000100990101000101, 110001000091000100011, 10001001099900110010001, 10010001099900110001001. - Max Alekseyev, Sep 18 2025

Links

Table of n, a(n) for n=1..15.

Example

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

Mathematica

Select[Range[3200000], !PalindromeQ[#] && PalindromeQ[#^(DivisorSigma[0, #]/2)] &] (* Amiram Eldar, Sep 02 2019 *)

Prog

(PARI) ispal(n) = my(d=digits(n)); d == Vecrev(d);
isok(n) = !ispal(n) && ispal(vecprod(divisors(n)));

Crossrefs

Intersection of A029742 and A327325.

Cf. A002113, A007955, A075786.

Sequence in context: A316120 A261932 A364025 * A375139 A137263 A390600

Adjacent sequences: A324038 A324039 A324040 * A324042 A324043 A324044

Keyword

nonn,base,more

Author

Michel Marcus, Sep 02 2019

Extensions

a(8)-a(15) from Giovanni Resta, Sep 04 2019

Status

approved