login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A062687 Numbers all of whose divisors are palindromic. 11
1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 44, 55, 66, 77, 88, 99, 101, 121, 131, 151, 181, 191, 202, 242, 262, 303, 313, 353, 363, 373, 383, 393, 404, 484, 505, 606, 626, 707, 727, 757, 787, 797, 808, 909, 919, 929, 939, 1111, 1331, 1441, 1661, 1991, 2222, 2662 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Indranil Ghosh, Table of n, a(n) for n = 1..221

EXAMPLE

44 has divisors 1, 2, 4, 11, 22 and 44, all palindromes, so 44 is a member.

n=808: divisors={1,2,4,8,101,202,404,808}.

MAPLE

isA062687 := proc(n)

    for d in numtheory[divisors](n) do

        if not isA002113(d) then

            return false;

        end if;

    end do;

    true ;

end proc: # R. J. Mathar, Sep 09 2015

MATHEMATICA

palQ[n_]:=Module[{idn=IntegerDigits[n]}, idn==Reverse[idn]]; Select[Range[ 2750], And@@palQ/@Divisors[#]&] (* Harvey P. Dale, Feb 27 2012 *)

PROG

(PARI) isok(n) = {d = divisors(n); rd = vector(#d, i, subst(Polrev(digits(d[i])), x, 10)); (d == rd); } \\ Michel Marcus, Oct 10 2014

CROSSREFS

Cf. A087991, A084325.

Subsequence of A002113.

Sequence in context: A110785 A193413 A087992 * A109882 A109872 A030285

Adjacent sequences:  A062684 A062685 A062686 * A062688 A062689 A062690

KEYWORD

base,easy,nonn

AUTHOR

Erich Friedman, Jul 04 2001

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified July 23 08:53 EDT 2017. Contains 289686 sequences.