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 A230006 Numbers n such that sigma(n) + phi(n) = reversal(n) + 1. 5
 1, 37, 225, 397, 11112722, 1309286244182 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS If p=4*10^m-3 is prime then p is in the sequence. a(7) > 10^13. - Giovanni Resta, Feb 08 2014 LINKS EXAMPLE sigma(37)+phi(37)=38+36=73+1=reversal(37)+1. MATHEMATICA r[n_] := FromDigits[Reverse[IntegerDigits[n]]]; Do[If[DivisorSigma[1, n] + EulerPhi[n] == r[n]+1, Print[n]], {n, 1000000000}] CROSSREFS Cf. A000010, A000203, A004086, A230004, A230005. Sequence in context: A327033 A052166 A142010 * A284987 A133958 A088544 Adjacent sequences:  A230003 A230004 A230005 * A230007 A230008 A230009 KEYWORD nonn,base,more AUTHOR Farideh Firoozbakht, Dec 02 2013 EXTENSIONS a(6) from Giovanni Resta, Feb 06 2014 STATUS approved

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Last modified December 5 15:06 EST 2021. Contains 349557 sequences. (Running on oeis4.)