This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A066458 #16 Aug 14 2020 06:43:07 %S A066458 12,22,132,34543,612415,27236725,27236752,311162281,311163138, %T A066458 327361548,9237866583,17499331217,17499551725,36475999489,36475999498 %N A066458 Numbers n such that Sum_{d runs through digits of n} d^d = pi(n) (cf. A000720). %C A066458 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 %H A066458 C. Caldwell and G. L. Honaker, Jr., <a href="https://utm.edu/staff/caldwell/preprints/6521.pdf">Is pi(6521)=6!+5!+2!+1! unique?</a> %e A066458 a(3)=132 because there are exactly 1^1+3^3+2^2 (or 32) prime numbers less than or equal to 132. %t A066458 Do[ If[ Apply[Plus, IntegerDigits[n]^IntegerDigits[n]] == PrimePi[n], Print[n]], {n, 1, 10^7} ] %Y A066458 Cf. A105328, A105329. %K A066458 base,nonn,fini,full %O A066458 1,1 %A A066458 _Jason Earls_, Jan 02 2002 %E A066458 More terms from _Robert G. Wilson v_, Jan 15 2002 %E A066458 Terms 27236725 onwards from _Farideh Firoozbakht_, Apr 21 2005 and Sep 17 2005 %E A066458 Sequence completed by _Farideh Firoozbakht_, Sep 23 2005