A242571 - cp's OEIS frontend

A242571 Triangular numbers T such that sum of the factorials of digits of T is semiprime.

n	a(n)
1	3
2	15
3	28
4	105
5	120
6	171
7	210
8	231
9	406
10	561
11	741
12	820
13	990
14	1081
15	1275
16	1378
17	1485
18	1540
19	1596
20	1953
21	2211
22	2485
23	2775
24	3003
25	3240
26	3321
27	3741
28	3916
29	4005
30	4371
31	4560
32	4851
33	5460
34	6105
35	6903
36	7381
37	7750
38	8001
39	8128
40	8515
41	9316
42	9591
43	9730
44	10153
45	10440
46	10878

[3, 15, 28, 105, 120, 171, 210, 231, 406, 561, 741, 820, 990, 1081, 1275, 1378, 1485, 1540, 1596, 1953, 2211, 2485, 2775, 3003, 3240, 3321, 3741, 3916, 4005, 4371, 4560, 4851, 5460, 6105, 6903, 7381, 7750, 8001, 8128, 8515, 9316, 9591, 9730, 10153, 10440, 10878]

cp's OEIS Frontend

A242571 Triangular numbers T such that sum of the factorials of digits of T is semiprime.

Table of values

List of values