%I #17 Aug 25 2024 11:17:40
%S 1,1,1,1,1,2,1,2,2,2,1,5,1,2,3,4,1,6,1,5,3,2,1,10,2,2,4,5,1,9,1,8,3,2,
%T 3,14,1,2,3,12,1,10,1,5,8,2,1,20,2,6,3,5,1,16,3,12,3,2,1,22,1,2,8,16,
%U 3,10,1,5,3,9,1,30,1,2,8,5,3,10,1,26,8,2,1,26,3,2,3,12,1,29
%N a(n) is the number of integers of the form d_1 - d_2 + d_3 - d_4 + ... + (-1)^k d_k, where n = d_1 > d_2 > ... > d_k = 1, d_{i+1} divides d_i for 1 <= i <= k-1.
%H Jianing Song, <a href="/A375624/b375624.txt">Table of n, a(n) for n = 1..10000</a>
%e n = 4: 3 = 4 - 1;
%e n = 6: 4 = 6 - 3 + 1, 5 = 6 - 1;
%e n = 8: 5 = 8 - 4 + 1, 7 = 8 - 1;
%e n = 9: 7 = 9 - 3 + 1, 8 = 9 - 1;
%e n = 10: 6 = 10 - 5 + 1, 9 = 10 - 1.
%o (PARI) \\ For the PARI program giving the set of such numbers of each n, see A375626.
%Y Cf. A375626.
%K nonn
%O 1,6
%A _Jianing Song_, Aug 21 2024