A138196 - cp's OEIS frontend

A138196 Number of different ways n! can be represented as the difference of two squares; also, for n >= 4, half the number of positive integer divisors of n!/4.

n	a(n)
1	1
2	0
3	0
4	2
5	4
6	9
7	18
8	36
9	60
10	105
11	210
12	324
13	648
14	1080
15	1680
16	2352
17	4704
18	6480
19	12960
20	18360
21	27200
22	43200
23	86400
24	110880
25	155232
26	243936
27	310464
28	423360
29	846720
30	1080000
31	2160000
32	2592000
33	3686400
34	5713920
35	7713792
36	9237888
37	18475776

[1, 0, 0, 2, 4, 9, 18, 36, 60, 105, 210, 324, 648, 1080, 1680, 2352, 4704, 6480, 12960, 18360, 27200, 43200, 86400, 110880, 155232, 243936, 310464, 423360, 846720, 1080000, 2160000, 2592000, 3686400, 5713920, 7713792, 9237888, 18475776]

cp's OEIS Frontend

A138196 Number of different ways n! can be represented as the difference of two squares; also, for n >= 4, half the number of positive integer divisors of n!/4.

Table of values

List of values