A121367 - cp's OEIS frontend

A121367 a(1) = a(2) = 1, a(n) = a(n-1) + A007947(a(n-2)) for n >= 3, i.e., a(n) = a(n-1) plus the largest squarefree divisor of a(n-2).

n	a(n)
1	1
2	1
3	2
4	3
5	5
6	8
7	13
8	15
9	28
10	43
11	57
12	100
13	157
14	167
15	324
16	491
17	497
18	988
19	1485
20	1979
21	2144
22	4123
23	4257
24	8380
25	9799
26	13989
27	23788
28	37777
29	49671
30	87448
31	104005
32	125867
33	229872
34	355739
35	384473
36	740212
37	1124685
38	1494791
39	1536446
40	3031237
41	4567683
42	7598920

[1, 1, 2, 3, 5, 8, 13, 15, 28, 43, 57, 100, 157, 167, 324, 491, 497, 988, 1485, 1979, 2144, 4123, 4257, 8380, 9799, 13989, 23788, 37777, 49671, 87448, 104005, 125867, 229872, 355739, 384473, 740212, 1124685, 1494791, 1536446, 3031237, 4567683, 7598920]

cp's OEIS Frontend

A121367 a(1) = a(2) = 1, a(n) = a(n-1) + A007947(a(n-2)) for n >= 3, i.e., a(n) = a(n-1) plus the largest squarefree divisor of a(n-2).

Table of values

List of values