A289979 - cp's OEIS frontend

A289979 Define two sequences n1(i) and n2(i) by the recurrences n1(i) = n1(i-1) + digsum(n2(i-1)), n2(i) = n2(i-1) + digsum(n1(i-1)), with initial values n1(1) = n and n2(1) = 0. Then a(n) is the smallest m such that n1(i) = n2(i) = m for some i, or -1 if no such m exists.

n	a(n)
1	1
2	2
3	3
4	4
5	5
6	6
7	7
8	8
9	9
10	86
11	86
12	42
13	86
14	20
15	42
16	53
17	86
18	108
19	20
20	110
21	222
22	110
23	31
24	222
25	310
26	110
27	288
28	31
29	97
30	75
31	154
32	64
33	75
34	692
35	154
36	468
37	64
38	176
39	75
40	389
41	367
42	132
43	187
44	389
45	648
46	367
47	209
48	132
49	211
50	1772
51	411
52	446
53	1715
54	828
55	1772
56	7150
57	411
58	413

[1, 2, 3, 4, 5, 6, 7, 8, 9, 86, 86, 42, 86, 20, 42, 53, 86, 108, 20, 110, 222, 110, 31, 222, 310, 110, 288, 31, 97, 75, 154, 64, 75, 692, 154, 468, 64, 176, 75, 389, 367, 132, 187, 389, 648, 367, 209, 132, 211, 1772, 411, 446, 1715, 828, 1772, 7150, 411, 413]

cp's OEIS Frontend

A289979 Define two sequences n1(i) and n2(i) by the recurrences n1(i) = n1(i-1) + digsum(n2(i-1)), n2(i) = n2(i-1) + digsum(n1(i-1)), with initial values n1(1) = n and n2(1) = 0. Then a(n) is the smallest m such that n1(i) = n2(i) = m for some i, or -1 if no such m exists.

Table of values

List of values