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A046352 Composite numbers whose sum of prime factors is palindromic (counted with multiplicity).

%I A046352 #18 Jan 10 2023 16:24:35
%S A046352 4,6,8,9,10,12,14,15,16,18,20,24,27,28,40,45,48,54,57,62,85,102,106,
%T A046352 116,121,123,182,194,218,259,260,278,292,298,305,308,312,351,358,366,
%U A046352 370,388,403,413,415,428,440,444,483,495,498,508,528,548,568,575,590
%N A046352 Composite numbers whose sum of prime factors is palindromic (counted with multiplicity).
%H A046352 R. J. Mathar, <a href="/A046352/b046352.txt">Table of n, a(n) for n = 1..2014</a>
%e A046352 116 = 2 * 2 * 29 -> 2 + 2 + 29 = 33 and 33 is a palindrome.
%p A046352 n := 1 ;
%p A046352 for i from 2 to 30000 do
%p A046352     if not isprime(i) then
%p A046352         sof := A001414(i) ;
%p A046352         if isA002113(sof) then
%p A046352             printf("%d %d\n",n,i) ;
%p A046352             n := n+1 ;
%p A046352         end if;
%p A046352     end if;
%p A046352 end do: # _R. J. Mathar_, Sep 09 2015
%t A046352 palQ[n_]:=Reverse[x=IntegerDigits[n]]==x; Select[Range[4,590],!PrimeQ[#]&&palQ[Total[Times@@@FactorInteger[#]]]&] (* _Jayanta Basu_, Jun 05 2013 *)
%t A046352 Select[Range@1000,CompositeQ@#&&PalindromeQ[Dot@@Transpose[FactorInteger@#]]&]  (* _Hans Rudolf Widmer_, Dec 21 2022 *)
%Y A046352 Cf. A046353, A046354.
%K A046352 nonn,base
%O A046352 1,1
%A A046352 _Patrick De Geest_, Jun 15 1998