A366864 - OEIS

%I #12 Oct 26 2023 10:25:37

%S 4,5,10,13,24,39,84,168,370,836,1998,4622,11284,28151,53565,138230,

%T 334125,659741,1716635,3977282,10430384,27132843,71588934,189472352,

%U 505341104,1353331592

%N Numbers m such that A366470(m) > A366470(m-1).

%C Inspired by N. J. A. Sloane's remark about the graph of A366470 consisting of decreasing segments. Terms mark the beginning of these segments in the graph of A366470. Appears to grow exponentially. Terms seem to be near the values of t_i described in Sloane's sketch at A364054.

%H Seqfan discussion, <a href="http://list.seqfan.eu/pipermail/seqfan/2023-October/074906.html">Re: Ali Sada's A364054</a>.

%o (Python)

%o from itertools import count, islice

%o from sympy import nextprime

%o def A366864_gen(): # generator of terms

%o     a, aset, p = 1, {0,1}, 2

%o     for i in count(3):

%o         for b in count(a,p):

%o             if b not in aset:

%o                 aset.add(b)

%o                 c = b%(p:=nextprime(p))

%o                 if c > a:

%o                     yield i

%o                 a = c

%o                 break

%o A366864_list = list(islice(A366864_gen(),20))

%Y Cf. A364054, A366470.

%K nonn,more

%O 1,1

%A _Chai Wah Wu_, Oct 25 2023