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.

A050768 Iterated procedure 'composite k added to sum of its prime factors reaches a prime' yields 1 skipped prime.

This page as a plain text file.
%I A050768 #8 Oct 17 2019 22:44:53
%S A050768 6,20,48,112,320,1326,1400,4165,4374,10395,12852,15827,20412,23232,
%T A050768 24300,24990,25000,27200,27300,31407,33660,34965,38480,41553,42525,
%U A050768 50688,53508,65450,66000,68400,69498
%N A050768 Iterated procedure 'composite k added to sum of its prime factors reaches a prime' yields 1 skipped prime.
%e A050768 a(2)=20 + (2+2+5) = ending prime 29. Between 20 and 29 lies exactly one prime 23.
%t A050768 aQ[n_]:=NextPrime[NestWhile[#+Total[Times@@@FactorInteger[#]]&,n,!PrimeQ[#]&],-1]==NextPrime[n]; Select[Range[70000],!PrimeQ[#]&&aQ[#]&] (* _Jayanta Basu_, May 31 2013 *)
%Y A050768 Cf. A050703, A050710.
%K A050768 nonn
%O A050768 0,1
%A A050768 _Patrick De Geest_, Sep 15 1999