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 A230028 Numbers n such that phi(n) = reversal(n-20). 1
 104, 824, 800024, 8000024, 84803024, 8483021444 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS If p=10^m+3 is prime then 8*p is in the sequence. 84803024 is the only known term of the sequence which is not of this form. a(7) > 10^11. - Giovanni Resta, Dec 13 2013 LINKS EXAMPLE phi(104)=48=reversal(84)=reversal(104-20). MATHEMATICA Do[If[EulerPhi[n]==FromDigits[Reverse[IntegerDigits[n-20]]], Print[n]], {n, 21, 90000000}] CROSSREFS Cf. A000010, A004086. Sequence in context: A206014 A106298 A337145 * A340898 A132434 A187589 Adjacent sequences: A230025 A230026 A230027 * A230029 A230030 A230031 KEYWORD nonn,base,bref,more AUTHOR Farideh Firoozbakht, Dec 13 2013 EXTENSIONS a(6) from Giovanni Resta, Dec 13 2013 STATUS approved

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Last modified January 31 11:20 EST 2023. Contains 359971 sequences. (Running on oeis4.)