A258813 - cp's OEIS frontend

A258813 Numbers k with the property that it is possible to write the base 2 expansion of k 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) + sigma (b) = sigma(k) - k.

n	a(n)
1	9
2	15
3	27
4	39
5	51
6	77
7	143
8	207
9	329
10	377
11	473
12	611
13	903
14	1241
15	1243
16	1273
17	1437
18	1591
19	2117
20	2303
21	2975
22	4189
23	8401
24	8657
25	11993
26	13849
27	15611
28	16771
29	18239
30	18599
31	19359
32	25331
33	28877
34	37291
35	41747
36	41807
37	61549
38	67037
39	72601
40	82169
41	83411
42	83711
43	87449
44	99329

[9, 15, 27, 39, 51, 77, 143, 207, 329, 377, 473, 611, 903, 1241, 1243, 1273, 1437, 1591, 2117, 2303, 2975, 4189, 8401, 8657, 11993, 13849, 15611, 16771, 18239, 18599, 19359, 25331, 28877, 37291, 41747, 41807, 61549, 67037, 72601, 82169, 83411, 83711, 87449, 99329]

cp's OEIS Frontend

A258813 Numbers k with the property that it is possible to write the base 2 expansion of k 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) + sigma (b) = sigma(k) - k.

Table of values

List of values