A005269 - cp's OEIS frontend

A005269 a(n) = number of length-n sequences s with s[1]=1, s[2]=1, s[k-1] <=s[k] <= s[k-2]+s[k-1] (s is called a sub-Fibonacci sequence of length n).

n	a(n)
2	1
3	2
4	4
5	10
6	31
7	127
8	711
9	5621
10	64049
11	1067599
12	26287664
13	963023487
14	52766766100
15	4342736509018
16	538755914902622
17	101067429677072459
18	28751803102222498512
19	12436935036300286507123
20	8200693250120852291693833
21	8262592110164298068793701546

[1, 2, 4, 10, 31, 127, 711, 5621, 64049, 1067599, 26287664, 963023487, 52766766100, 4342736509018, 538755914902622, 101067429677072459, 28751803102222498512, 12436935036300286507123, 8200693250120852291693833, 8262592110164298068793701546]

cp's OEIS Frontend

A005269 a(n) = number of length-n sequences s with s[1]=1, s[2]=1, s[k-1] <=s[k] <= s[k-2]+s[k-1] (s is called a sub-Fibonacci sequence of length n).

Table of values

List of values