A336218 - OEIS

%I #14 Jul 15 2021 21:26:42

%S 1,3,1,1,2,2,5,14,2,14,2,14,2,2,2,1,2,2,2,2,4,2,2,4,2,65,2,2,2,6,25,2,

%T 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,39,26,2,2,2,2,2,2,2,2,2,2,2,2,2,2,

%U 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2

%N a(n) is the length of the cycle of the purely periodic unitary sigma aliquot cycles listed in A336216.

%C For the definition of unitary divisors see A034448. This sequence has been calculated from the table of 440 lines in the link of A327157 of _Antti Karttunen_. That table contains the numbers in 122 complete cycles and in 5 incomplete 2-cycles with values larger than number 27287260 in line 440 which results in the cumulative sum of 445 for the data listed in this sequence.

%H Hartmut F. W. Hoft, <a href="/A336218/a336218_1.pdf">Plot of 25th through 52nd pure unitary sigma aliquot cycles</a>

%e The first cycle of size 14 = a(8) starts at position: 1 + (1+3+1+1+2+2+5) = 16 in A336216.

%Y Cf. A034448, A327157, A336216, A336219.

%K nonn

%O 1,2

%A _Hartmut F. W. Hoft_, Jul 12 2020