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A046360
Composite palindromes divisible by the palindromic sum of their prime factors (counted with multiplicity).
3
4, 5445, 234432, 585585, 888888, 951159, 999999, 1345431, 2554552, 4620264, 5842485, 6151516, 9704079, 12333321, 40199104, 42266224, 42666624, 44088044, 46355364, 63599536, 63633636, 420838024, 424848424, 631949136, 649363946
OFFSET
1,1
EXAMPLE
649363946 = 2 * 7 * 11 * 83 * 101 * 503 -> Sum of factors is palindrome 707 -> 649363946 / 707 = 918478 exactly.
MATHEMATICA
palQ[n_]:= Reverse[x=IntegerDigits[n]] == x; t={}; Do[If[!PrimeQ[n] && And@@palQ/@{n, y=Total[Times@@@FactorInteger[n]]} && IntegerQ[n/y], AppendTo[t, n]], {n, 4, 6*10^6}]; t (* Jayanta Basu, Jun 05 2013 *)
pspfQ[n_]:=Module[{sf=Total[Times@@@FactorInteger[n]]}, CompositeQ[ n] && AllTrue[{n, sf}, PalindromeQ]&&IntegerQ[n/sf]]; Select[Range[ 2, 65*10^7], pspfQ] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Nov 24 2019 *)
CROSSREFS
Sequence in context: A306962 A102205 A283663 * A367942 A079232 A338665
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Jun 15 1998
EXTENSIONS
Definition clarified by Harvey P. Dale, Nov 24 2019
STATUS
approved