A356319 - OEIS

A356319

Numbers k such that {the least j >= k for which k and A276086(k+j) are coprime} is larger than 0, but less than k, where A276086 is the primorial base exp-function.

%I #7 Nov 04 2022 11:27:07

%S 9,20,21,25,27,33,39,40,45,50,51,55,57,69,75,80,81,85,87,93,99,100,

%T 110,111,112,115,117,119,123,126,129,130,133,135,140,141,145,147,153,

%U 159,160,161,165,168,170,171,175,177,182,183,189,190,195,196,200,201,203,205,207,213,219,225,230,235,237,243,245,249

%N Numbers k such that {the least j >= k for which k and A276086(k+j) are coprime} is larger than 0, but less than k, where A276086 is the primorial base exp-function.

%C Numbers k for which 0 < A356302(k) < k, or equally, for which k < A356309(k) < 2*k.

%H <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>

%o (PARI) isA356319(n) = { my(u=A356302(n)); (u && (u<n)); };

%Y Subsequence of A356317, which is a subsequence of A324584.

%Y Cf. A276086, A356302, A356309.

%K nonn

%O 1,1

%A _Antti Karttunen_, Nov 04 2022