A365717 - OEIS

%I #9 Sep 17 2023 11:24:38

%S 1,2,2,2,4,6,10,8,4,2,14,6,4,20,12,50,16,18,6,28,30,8,40,24,100,32,8,

%T 2,22,10,10,44,42,70,56,12,4,98,18,12,140,60,250,80,36,18,196,150,16,

%U 200,48,500,64,54,6,110,30,20,88,84,350,112,90,8,490,54,24,280,120,1250,160,72,36,392,300,32,400,96,1000

%N a(n) is the least k such that A003961^i(k) = A356867(1+n) for some i >= 0, where A003961^i denotes the i-th iterate of prime shift, and A356867 is Sycamore's Doudna variant D(3).

%H Antti Karttunen, <a href="/A365717/b365717.txt">Table of n, a(n) for n = 0..19683</a>

%F a(n) = A348717(A356867(1+n)).

%o (PARI)

%o A348717(n) = if(1==n, 1, my(f = factor(n), k = primepi(f[1, 1])-1); for (i=1, #f~, f[i, 1] = prime(primepi(f[i, 1])-k)); factorback(f));

%o A365717(n) = A348717(A356867(1+n)); \\ Needs also program from A356867.

%Y Cf. A348717, A356867, A365718 (rgs-transform), A365719, A365721, A365722.

%K nonn

%O 0,2

%A _Antti Karttunen_, Sep 17 2023