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.

A125832 Numbers k which have exactly 14 representations as a product of two palindromes.

This page as a plain text file.
%I A125832 #12 Aug 02 2025 12:39:28
%S A125832 5426124,8139186,20017998,21999978,26690664,26888862,29333304,
%T A125832 49821684,73267326,97689768,98666568,146534652,147999852,220197978,
%U A125832 271333062,274019262,320221902,403696293,471535064,489372884,516019504,518221704
%N A125832 Numbers k which have exactly 14 representations as a product of two palindromes.
%e A125832 26888862 is in the sequence since 26888862 =
%e A125832  1*26888862 = 2*13444431 = 11*2444442 = 22*1222221 = 111*242242 = 121*222222 = 222*121121 =
%e A125832  242*111111 = 1001*26862 = 1221*22022 = 1331*20202 = 2002*13431 = 2442*11011 = 2662*10101.
%t A125832 f[n_]:=f[n]=Length[Select[Divisors[n],#<=n^(1/2)&&FromDigits[ Reverse[IntegerDigits[ # ]]]==#&&FromDigits[Reverse[IntegerDigits [n/# ]]]==n/#&]];Do[If[f[n]==14,Print[n]],{n,50000000}]
%Y A125832 Cf. A116993, A125833, A125834.
%K A125832 base,nonn
%O A125832 1,1
%A A125832 _Farideh Firoozbakht_, Dec 10 2006
%E A125832 a(9)-a(22) from _Donovan Johnson_, Aug 05 2009