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

 

Logo

The October issue of the Notices of the Amer. Math. Soc. has an article about the OEIS.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A046355 Composite numbers with only palindromic prime factors whose sum is palindromic (counted with multiplicity). 4
4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20, 24, 27, 28, 40, 45, 48, 54, 121, 308, 440, 495, 528, 594, 735, 784, 875, 882, 1050, 1120, 1250, 1260, 1331, 1344, 1500, 1512, 1600, 1701, 1800, 1920, 2025, 2048, 2101, 2121, 2160, 2304, 2430, 2525, 2592, 2751, 2916, 3030 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Subsequence of the numbers k in A046349 such that A262049(k) is in A002113. - R. J. Mathar, Sep 09 2015

LINKS

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

EXAMPLE

3030 = 2 * 3 * 5 * 101 -> 2 + 3 + 5 + 101 = 111 and 111 is a palindrome.

MAPLE

isA046355 := proc(n)

    local sofpp ;

    if isA046349(n) then

        sofpp := A262049(n) ;

        isA002113(sofpp) ;

    else

        false;

    end if;

end proc:

for n from 2 to 400 do

    if isA046355(n) then

        printf("%d, ", n);

    end if;

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

MATHEMATICA

palQ[n_] := Reverse[x=IntegerDigits[n]] == x; Select[Range[4, 3100], !PrimeQ[#] && And@@palQ/@Join[{Total[Times@@@(x=FactorInteger[#])]}, First/@x]&] (* Jayanta Basu, Jun 05 2013 *)

CROSSREFS

Cf. A046356, A046357.

Sequence in context: A070807 A246282 A046352 * A163122 A202259 A050655

Adjacent sequences:  A046352 A046353 A046354 * A046356 A046357 A046358

KEYWORD

nonn,base

AUTHOR

Patrick De Geest, Jun 15 1998.

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 September 25 21:12 EDT 2018. Contains 315425 sequences. (Running on oeis4.)