A069921 - cp's OEIS frontend

A069921 Define C(n) by the recursion C(0) = 1 + I where I^2 = -1, C(n+1) = 1/(1+C(n)); then a(n) = (-1)^n/Im(C(n)) where Im(z) is the imaginary part of the complex number z.

n	a(n)
0	1
1	5
2	10
3	29
4	73
5	194
6	505
7	1325
8	3466
9	9077
10	23761
11	62210
12	162865
13	426389
14	1116298
15	2922509
16	7651225
17	20031170
18	52442281
19	137295677
20	359444746
21	941038565
22	2463670945
23	6449974274
24	16886251873
25	44208781349
26	115740092170
27	303011495165
28	793294393321

[1, 5, 10, 29, 73, 194, 505, 1325, 3466, 9077, 23761, 62210, 162865, 426389, 1116298, 2922509, 7651225, 20031170, 52442281, 137295677, 359444746, 941038565, 2463670945, 6449974274, 16886251873, 44208781349, 115740092170, 303011495165, 793294393321]

cp's OEIS Frontend

A069921 Define C(n) by the recursion C(0) = 1 + I where I^2 = -1, C(n+1) = 1/(1+C(n)); then a(n) = (-1)^n/Im(C(n)) where Im(z) is the imaginary part of the complex number z.

Table of values

List of values