A373756 - cp's OEIS frontend

A373756 Table read by antidiagonals: T(n,k) is the smallest m > 1 such that m^2 - 1 and m^2 + 1 have 2n and 2k divisors, respectively, or -1 if no such m exists.

n	a(n)
1	2
2	4
3	-1
4	10
5	3
6	-1
7	14
8	8
9	18
10	-1
11	28560
12	5
13	168
14	72
15	-1
16	26
17	9
18	32
19	360
20	16068
21	-1
22	25071688922457240
23	15
24	7
25	68
26	369465818568
27	1620
28	-1
29	56
30	728
31	332
32	28398240
33	182
34	744768
35	1407318
36	-1
37	170
38	11
39	161245807967271241368
40	98
41	248872305817685706212070112080
42	132
43	4175536688568
44	642
45	-1

[2, 4, -1, 10, 3, -1, 14, 8, 18, -1, 28560, 5, 168, 72, -1, 26, 9, 32, 360, 16068, -1, 25071688922457240, 15, 7, 68, 369465818568, 1620, -1, 56, 728, 332, 28398240, 182, 744768, 1407318, -1, 170, 11, 161245807967271241368, 98, 248872305817685706212070112080, 132, 4175536688568, 642, -1]

cp's OEIS Frontend

A373756 Table read by antidiagonals: T(n,k) is the smallest m > 1 such that m^2 - 1 and m^2 + 1 have 2n and 2k divisors, respectively, or -1 if no such m exists.

Table of values

List of values