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.

A369000 a(n) is the number of integers, not semiprimes, whose arithmetic derivative is equal to the n-th primorial.

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%I A369000 #10 Jan 18 2024 18:13:10
%S A369000 0,0,0,0,0,0,1,1,0,0,2,9,18
%N A369000 a(n) is the number of integers, not semiprimes, whose arithmetic derivative is equal to the n-th primorial.
%C A369000 a(n) = number of solutions k to equation A003415(k) = A002110(n) with A001222(k) > 2.
%H A369000 Antti Karttunen, <a href="/A369000/a369000.txt">PARI-program</a>
%H A369000 <a href="/index/Pri#primorial_numbers">Index entries for sequences related to primorial numbers</a>
%F A369000 a(n) = A351029(n) - A116979(n).
%o A369000 (PARI) \\ See the attached PARI-program.
%Y A369000 Cf. A001222, A002110, A003415, A116979, A351029, A366890 (solutions themselves).
%K A369000 nonn,hard,more
%O A369000 1,11
%A A369000 _Antti Karttunen_, Jan 16 2024