A259831 - cp's OEIS frontend

A259831 Numbers n with the property that it is possible to write the base 2 expansion of n as concat(a_2,b_2), with a_2>0 and b_2>0 such that, converting a_2 and b_2 to base 10 as a and b, we have (sigma(a)-a)*(sigma(b)-b) = n.

n	a(n)
1	216
2	13296
3	13464
4	14416
5	51480
6	235200
7	575484
8	578592
9	585000
10	1032656
11	1121400
12	1599552
13	4190364
14	4786110
15	8365968
16	11268688
17	13010634
18	13253436
19	21835624
20	22108784
21	23896320
22	136311840
23	152820243
24	160380496
25	170073324
26	295999900
27	421686580
28	445421664

[216, 13296, 13464, 14416, 51480, 235200, 575484, 578592, 585000, 1032656, 1121400, 1599552, 4190364, 4786110, 8365968, 11268688, 13010634, 13253436, 21835624, 22108784, 23896320, 136311840, 152820243, 160380496, 170073324, 295999900, 421686580, 445421664]

cp's OEIS Frontend

A259831 Numbers n with the property that it is possible to write the base 2 expansion of n as concat(a_2,b_2), with a_2>0 and b_2>0 such that, converting a_2 and b_2 to base 10 as a and b, we have (sigma(a)-a)*(sigma(b)-b) = n.

Table of values

List of values