login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A046366 Composite numbers divisible by the palindromic sum of their palindromic prime factors (counted with multiplicity). 2

%I #19 Oct 11 2019 04:05:35

%S 4,16,27,308,440,528,594,5445,5808,6534,8085,9702,11550,13860,14784,

%T 16500,16632,18711,19800,21120,22275,23760,25344,26730,28512,32076,

%U 37268,53240,63888,94864,135520,152460,162624,181500,182952,193600

%N Composite numbers divisible by the palindromic sum of their palindromic prime factors (counted with multiplicity).

%C The subsequence of numbers k of A046355 such that A262049(k) divides k. - _R. J. Mathar_, Sep 09 2015

%H Giovanni Resta, <a href="/A046366/b046366.txt">Table of n, a(n) for n = 1..1387</a> (terms < 10^10)

%e 1041714 = 2 * 3^3 * 101 * 191 -> Sum of factors is 303 -> 1041714 / 303 = 3438 exactly.

%p isA046366 := proc(n)

%p local sofpp ;

%p if isA046355(n) then

%p sofpp := A262049(n) ;

%p if modp(n,sofpp) = 0 then

%p true;

%p else

%p false;

%p end if;

%p else

%p false;

%p end if;

%p end proc:

%p for n from 2 to 1000 do

%p if isA046366(n) then

%p printf("%d,",n) ;

%p end if;

%p end do: # _R. J. Mathar_, Sep 09 2015

%t palQ[n_]:=Reverse[x=IntegerDigits[n]]==x; Select[Range[4,10^5],!PrimeQ[#]&&And@@palQ/@Join[{y=Total[Times@@@(x=FactorInteger[#])]},First/@x]&&IntegerQ[#/y]&](* _Jayanta Basu_, Jun 05 2013 *)

%Y Cf. A046367.

%K nonn,base

%O 1,1

%A _Patrick De Geest_, Jun 15 1998

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 22 14:17 EDT 2024. Contains 373587 sequences. (Running on oeis4.)