A187983 - cp's OEIS frontend

A187983 Number of nondecreasing arrangements of n numbers x(i) in -(n+2)..(n+2) with the sum of sign(x(i))*2^|x(i)| zero.

n	a(n)
1	0
2	4
3	9
4	30
5	111
6	355
7	1257
8	4357
9	15146
10	53379
11	187699
12	663631
13	2352610
14	8356208
15	29754352
16	106127185
17	379166226
18	1356700796
19	4860763378
20	17436188166
21	62613987171
22	225072940410
23	809789751003
24	2915986488761
25	10508369260118
26	37896284981596
27	136756217644237
28	493817776063606

[0, 4, 9, 30, 111, 355, 1257, 4357, 15146, 53379, 187699, 663631, 2352610, 8356208, 29754352, 106127185, 379166226, 1356700796, 4860763378, 17436188166, 62613987171, 225072940410, 809789751003, 2915986488761, 10508369260118, 37896284981596, 136756217644237, 493817776063606]

cp's OEIS Frontend

A187983 Number of nondecreasing arrangements of n numbers x(i) in -(n+2)..(n+2) with the sum of sign(x(i))*2^|x(i)| zero.

Table of values

List of values