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 A066458 Numbers n such that Sum_{d runs through digits of n} d^d = pi(n) (cf. A000720). 0
 12, 22, 132, 34543, 612415, 27236725, 27236752, 311162281, 311163138, 327361548, 9237866583, 17499331217, 17499551725, 36475999489, 36475999498 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Note that only two terms, namely 34543 & 17499331217 are primes. So we have: 34543=prime(3^3+4^4+5^5+4^4+3^3), 17499331217=prime(1^1+7^7+4^4+9^9+9^9+3^3+3^3+1^1+2^2+1^1+7^7) and there is no other such prime. - Farideh Firoozbakht, Sep 23 2005. LINKS C. Caldwell and G. L. Honaker, Jr., Is pi(6521)=6!+5!+2!+1! unique? EXAMPLE a(3)=132 because there are exactly 1^1+3^3+2^2 (or 32) prime numbers less than or equal to 132. MATHEMATICA Do[ If[ Apply[Plus, IntegerDigits[n]^IntegerDigits[n]] == PrimePi[n], Print[n]], {n, 1, 10^7} ] CROSSREFS Cf. A105328, A105329. Sequence in context: A298323 A299216 A227072 * A246342 A101104 A114455 Adjacent sequences:  A066455 A066456 A066457 * A066459 A066460 A066461 KEYWORD base,nonn,fini,full AUTHOR Jason Earls, Jan 02 2002 EXTENSIONS More terms from Robert G. Wilson v, Jan 15 2002 Terms 27236725 onwards from Farideh Firoozbakht, Apr 21 2005 and Sep 17 2005 Sequence completed by Farideh Firoozbakht, Sep 23 2005 STATUS approved

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Last modified February 20 20:30 EST 2020. Contains 332084 sequences. (Running on oeis4.)