A327325 Integers with palindromic product of divisors.

1, 2, 3, 4, 5, 7, 11, 22, 26, 49, 101, 111, 121, 131, 151, 181, 191, 202, 313, 353, 373, 383, 727, 757, 787, 797, 919, 929, 1001, 1111, 2285, 10001, 10201, 10301, 10501, 10601, 11111, 11311, 11411, 12421, 12721, 12821, 13331, 13831, 13931, 14341, 14741, 15451

Offset: 1

Author

Jaroslav Krizek, Aug 30 2019

Keywords

• nonn
• base

Comments

Numbers m such that A007955(m) = pod(m) are in A002113.

Corresponding values of pod(a(n)): 1, 2, 3, 8, 5, 7, 11, 484, 676, 343, 101, 12321, 1331, 131, 151, ...

Examples

			A007955(49) = 343.
		

Links

• Giovanni Resta, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A002113, A007955, A028980, A180925, A244411.

Programs

Magma

[m: m in [1..10^5] | Intseq(&*[d: d in Divisors(m)], 10) eq Reverse(Intseq(&*[d: d in Divisors(m)], 10))];

Mathematica

Select[Range[16000], PalindromeQ[#^(DivisorSigma[0, #]/2)] &] (* Amiram Eldar, Aug 31 2019 *)

PARI

isok(n) = my(d=digits(vecprod(divisors(n)))); Vecrev(d) == d; \\ Michel Marcus, Sep 02 2019