cp's OEIS Frontend

A046366 Composite numbers divisible by the palindromic sum of their palindromic prime factors (counted with multiplicity).

%I A046366 #19 Oct 11 2019 04:05:35
%S A046366 4,16,27,308,440,528,594,5445,5808,6534,8085,9702,11550,13860,14784,
%T A046366 16500,16632,18711,19800,21120,22275,23760,25344,26730,28512,32076,
%U A046366 37268,53240,63888,94864,135520,152460,162624,181500,182952,193600
%N A046366 Composite numbers divisible by the palindromic sum of their palindromic prime factors (counted with multiplicity).
%C A046366 The subsequence of numbers k of A046355 such that A262049(k) divides k. - _R. J. Mathar_, Sep 09 2015
%H A046366 Giovanni Resta, <a href="/A046366/b046366.txt">Table of n, a(n) for n = 1..1387</a> (terms < 10^10)
%e A046366 1041714 = 2 * 3^3 * 101 * 191 -> Sum of factors is 303 -> 1041714 / 303 = 3438 exactly.
%p A046366 isA046366 := proc(n)
%p A046366     local sofpp ;
%p A046366     if isA046355(n) then
%p A046366         sofpp := A262049(n) ;
%p A046366         if modp(n,sofpp) = 0 then
%p A046366             true;
%p A046366         else
%p A046366             false;
%p A046366         end if;
%p A046366     else
%p A046366         false;
%p A046366     end if;
%p A046366 end proc:
%p A046366 for n from 2 to 1000 do
%p A046366     if isA046366(n) then
%p A046366         printf("%d,",n) ;
%p A046366     end if;
%p A046366 end do: # _R. J. Mathar_, Sep 09 2015
%t A046366 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 A046366 Cf. A046367.
%K A046366 nonn,base
%O A046366 1,1
%A A046366 _Patrick De Geest_, Jun 15 1998