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A046353 Odd composite numbers whose sum of prime factors is palindromic (counted with multiplicity).

%I A046353 #17 Apr 28 2018 07:44:27
%S A046353 9,15,27,45,57,85,121,123,259,305,351,403,413,415,483,495,575,597,627,
%T A046353 639,663,687,689,705,717,735,807,875,893,931,935,985,989,1073,1135,
%U A046353 1183,1203,1207,1263,1285,1293,1331,1353,1383,1385,1407,1473,1505,1545
%N A046353 Odd composite numbers whose sum of prime factors is palindromic (counted with multiplicity).
%H A046353 John Cerkan, <a href="/A046353/b046353.txt">Table of n, a(n) for n = 1..10000</a>
%e A046353 689 = 13 * 53 -> 13 + 53 = 66 and 66 is a palindrome.
%t A046353 palQ[n_]:=Reverse[x=IntegerDigits[n]]==x; Select[Range[9,1545,2],!PrimeQ[#]&&palQ[Total[Times@@@FactorInteger[#]]]&] (* _Jayanta Basu_, Jun 05 2013 *)
%o A046353 (Python)
%o A046353 from sympy import factorint
%o A046353 def is_046353(n):
%o A046353     if n % 2 == 0: return False
%o A046353     f = factorint(n)
%o A046353     if sum([f[i] for i in f]) < 2: return False
%o A046353     sfa = sum([i*f[i] for i in f])
%o A046353     if sfa == int(str(sfa)[::-1]): return True
%o A046353     return False # _John Cerkan_, Apr 24 2018
%Y A046353 Cf. A046352, A046354.
%K A046353 nonn,base
%O A046353 1,1
%A A046353 _Patrick De Geest_, Jun 15 1998
%E A046353 Name clarified and offset changed by _John Cerkan_, Apr 24 2018