Triangular numbers

Triangular numbers follow n(n+1)/2 and count dots that form a triangle.

10 = 1 + 2 + 3 + 4

#	n (number)	Detail
1	0	T0 = 0
2	1	T1 = 1
3	3	T2 = 3
4	6	T3 = 6
5	10	T4 = 10
6	15	T5 = 15
7	21	T6 = 21
8	28	T7 = 28
9	36	T8 = 36
10	45	T9 = 45
11	55	T10 = 55
12	66	T11 = 66
13	78	T12 = 78
14	91	T13 = 91
15	105	T14 = 105
16	120	T15 = 120
17	136	T16 = 136
18	153	T17 = 153
19	171	T18 = 171
20	190	T19 = 190
21	210	T20 = 210
22	231	T21 = 231
23	253	T22 = 253
24	276	T23 = 276
25	300	T24 = 300
26	325	T25 = 325
27	351	T26 = 351
28	378	T27 = 378
29	406	T28 = 406
30	435	T29 = 435
31	465	T30 = 465
32	496	T31 = 496
33	528	T32 = 528
34	561	T33 = 561
35	595	T34 = 595
36	630	T35 = 630
37	666	T36 = 666
38	703	T37 = 703
39	741	T38 = 741
40	780	T39 = 780
41	820	T40 = 820
42	861	T41 = 861
43	903	T42 = 903
44	946	T43 = 946
45	990	T44 = 990
46	1035	T45 = 1035
47	1081	T46 = 1081
48	1128	T47 = 1128
49	1176	T48 = 1176
50	1225	T49 = 1225
51	1275	T50 = 1275
52	1326	T51 = 1326
53	1378	T52 = 1378
54	1431	T53 = 1431
55	1485	T54 = 1485
56	1540	T55 = 1540
57	1596	T56 = 1596
58	1653	T57 = 1653
59	1711	T58 = 1711
60	1770	T59 = 1770
61	1830	T60 = 1830
62	1891	T61 = 1891
63	1953	T62 = 1953
64	2016	T63 = 2016
65	2080	T64 = 2080
66	2145	T65 = 2145
67	2211	T66 = 2211
68	2278	T67 = 2278
69	2346	T68 = 2346
70	2415	T69 = 2415
71	2485	T70 = 2485
72	2556	T71 = 2556
73	2628	T72 = 2628
74	2701	T73 = 2701
75	2775	T74 = 2775
76	2850	T75 = 2850
77	2926	T76 = 2926
78	3003	T77 = 3003
79	3081	T78 = 3081
80	3160	T79 = 3160
81	3240	T80 = 3240
82	3321	T81 = 3321
83	3403	T82 = 3403
84	3486	T83 = 3486
85	3570	T84 = 3570
86	3655	T85 = 3655
87	3741	T86 = 3741
88	3828	T87 = 3828
89	3916	T88 = 3916
90	4005	T89 = 4005
91	4095	T90 = 4095
92	4186	T91 = 4186
93	4278	T92 = 4278
94	4371	T93 = 4371
95	4465	T94 = 4465
96	4560	T95 = 4560
97	4656	T96 = 4656
98	4753	T97 = 4753
99	4851	T98 = 4851
100	4950	T99 = 4950