cp's OEIS Frontend

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.

A140174 Numbers k such that k = pi(k)*(sum of the digits of k).

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%I A140174 #11 May 22 2025 16:40:30
%S A140174 0,2,30,1122,24300
%N A140174 Numbers k such that k = pi(k)*(sum of the digits of k).
%C A140174 This sequence is a subsequence of A057809. There is no further term up to 16*10^6.
%C A140174 a(6) > 1.4*10^22, if it exists. - _Giovanni Resta_, Aug 31 2018
%e A140174 24300 = pi(24300) * (2+4+3+0+0) = 2700 * 9.
%t A140174 Select[Range[0,25000],PrimePi[#]Total[IntegerDigits[#]]==#&] (* _Harvey P. Dale_, Feb 13 2023 *)
%Y A140174 Cf. A000720, A007953, A057809, A140173.
%K A140174 base,more,nonn
%O A140174 1,2
%A A140174 _Farideh Firoozbakht_, May 15 2008