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.

A368703 a(n) is the least integer k whose arithmetic derivative is equal to the n-th primorial, or 0 if no such k exists.

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%I A368703 #25 Jan 20 2024 04:05:00
%S A368703 2,0,9,161,2189,29861,510221,1547371,79332523,9592991561,265257420749,
%T A368703 1102527599503
%N A368703 a(n) is the least integer k whose arithmetic derivative is equal to the n-th primorial, or 0 if no such k exists.
%C A368703 a(n) = the smallest integer k for which A003415(k) = A002110(n), and 0 if no such k exists.
%C A368703 If there are non-Goldbachian solutions (A366890) for some n, i.e., if A369000(n) > 0, then the smallest of them appears here as a value of a(n).
%C A368703 a(12) <= 25962012375103, a(13) <= 4958985803436403, a(14) <= 32442711864461575, a(15) <= 11758779158543465383. - _David A. Corneth_, Jan 17 2024
%H A368703 Antti Karttunen, <a href="/A369000/a369000.txt">PARI program</a>
%H A368703 <a href="/index/Pri#primorial_numbers">Index entries for sequences related to primorial numbers</a>
%F A368703 a(n) <= A368704(n).
%F A368703 For n<>1, A003415(a(n)) = A002110(n).
%e A368703 a(0) = 2 as the least number k such that A003415(k) = A002110(0) = 1 is 2.
%e A368703 a(1) = 0 as there is no number k such that A003415(k) = A002110(1) = 2.
%e A368703 a(7) = 1547371 as it is the least number k such that A003415(k) = A002110(7) = 510510. See also A366890.
%Y A368703 Cf. A002110, A003415, A351029, A368704, A366890, A369000.
%Y A368703 Cf. also A369243.
%K A368703 nonn,more,hard
%O A368703 0,1
%A A368703 _Antti Karttunen_, Jan 16 2024