A088000 a(n) is the sum of the palindromic divisors of n.

1, 3, 4, 7, 6, 12, 8, 15, 13, 8, 12, 16, 1, 10, 9, 15, 1, 21, 1, 12, 11, 36, 1, 24, 6, 3, 13, 14, 1, 17, 1, 15, 48, 3, 13, 25, 1, 3, 4, 20, 1, 19, 1, 84, 18, 3, 1, 24, 8, 8, 4, 7, 1, 21, 72, 22, 4, 3, 1, 21, 1, 3, 20, 15, 6, 144, 1, 7, 4, 15, 1, 33, 1, 3, 9, 7, 96, 12, 1, 20, 13, 3, 1, 23, 6, 3

Offset

1,2

Links

Indranil Ghosh, Table of n, a(n) for n = 1..10000

Example

n=14: a(14)=1+2+7=10;
n=101: a(101)=1+101=102;

Maple

A088000 := proc(n)
    a := 0 ;
    for d in numtheory[divisors](n) do
        if isA002113(d) then
            a := a+d ;
        end if;
    end do;
    a ;
end proc:
seq(A088000(n), n=1..100) ; # R. J. Mathar, Sep 09 2015

Mathematica

Table[Plus @@ Select[Divisors[k], Reverse[x = IntegerDigits[#]] == x &], {k, 86}] (* Jayanta Basu, Aug 12 2013 *)

Prog

(Python)
def ispal(n):
    return n==int(str(n)[::-1])
def A088000(n):
    s=0
    for i in range(1, n+1):
        if n%i==0 and ispal(i):
             s+=i
    return s
print([A088000(n) for n in range(1, 30)]) # Indranil Ghosh, Feb 10 2017
(PARI) a(n) = sumdiv(n, d, my(dd=digits(d)); if (Vecrev(dd) == dd, d)); \\ Michel Marcus, Apr 06 2020

Crossrefs

Cf. A062687 (all divisors are palindromic), A087990 (number of palindromic divisors).

Sequence in context: A353783 A367466 A093811 * A284344 A168338 A034690

Adjacent sequences: A087997 A087998 A087999 * A088001 A088002 A088003

Keyword

base,nonn

Author

Labos Elemer, Oct 14 2003

Status

approved