A202561 - OEIS

%I #11 Oct 30 2018 10:31:02

%S 60,5,2,33,31,6,124,10,97,127,41,90,12,18,11,28,12,70,93,36,38,72,52,

%T 83,60,38,14,16,5,59,21,82,16,29,30,8,28,44,14,32,56,7,9,130,43,30,7,

%U 119,96,87,66,21,5,15,34,34,58,101,84,47,41,131,7,75,44,20

%N Length of non-periodic part of the sequence defined by the recursion in A202211 and starting with a(1)=prime(n), a(2)=prime(n+1).

%C Among the first 10000 terms, the least term is a(3)=2, the largest terms are a(8109)=a(9716)=169.

%C Next records are a(16357)=178, a(27716)=181, a(62716)=191, a(84339)=196, a(358303)=197, a(470452)=214.

%C Is the sequence unbounded?

%H Zak Seidov, <a href="/A202561/b202561.txt">Table of n, a(n) for n = 1..10000</a>

%e a(1)=60, see A202211;

%e a(2)=5 because sequence is {3, 5, 17, 45, 45, 21, 25, 25, 21, 25, 25, 21, 25, 25, 21,..}, non-periodic part is npp={3, 5, 17, 45, 45} with #nnp=5, after which there is a periodic part pp={21, 25, 25} with #pp=3.

%Y Cf. A202211.

%K nonn

%O 1,1

%A _Zak Seidov_ and _Vladimir Shevelev_, Dec 21 2011