A087640 - cp's OEIS frontend

A087640 To obtain a(n+1), take the square of the n-th partial sum, minus the sum of the first n squared terms, then divide this difference by a(n); for all n>1, starting with a(0)=1, a(1)=1.

n	a(n)
0	1
1	1
2	2
3	5
4	10
5	23
6	48
7	107
8	228
9	501
10	1078
11	2353
12	5086
13	11067
14	23972
15	52087
16	112936
17	245225
18	531946
19	1154685
20	2505298
21	5437407
22	11798616
23	25605539
24	55563980
25	120581981
26	261668382
27	567850345
28	1232273510
29	2674156163
30	5803126348

[1, 1, 2, 5, 10, 23, 48, 107, 228, 501, 1078, 2353, 5086, 11067, 23972, 52087, 112936, 245225, 531946, 1154685, 2505298, 5437407, 11798616, 25605539, 55563980, 120581981, 261668382, 567850345, 1232273510, 2674156163, 5803126348]

cp's OEIS Frontend

A087640 To obtain a(n+1), take the square of the n-th partial sum, minus the sum of the first n squared terms, then divide this difference by a(n); for all n>1, starting with a(0)=1, a(1)=1.

Table of values

List of values