A221215 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

A221215 as a triangular array

												1
											6		5
										2		3		4
									15		14		13		12
								7		8		9		10		11
							28		27		26		25		24		23
						16		17		18		19		20		21		22
					45		44		43		42		41		40		39		38
				29		30		31		32		33		34		35		36		37
			66		65		64		63		62		61		60		59		58		57
		46		47		48		49		50		51		52		53		54		55		56
	91

A221215 as a square array

1	6	2	15	7	28	16	45	29	66	46	91
5	3	14	8	27	17	44	30	65	47
4	13	9	26	18	43	31	64	48
12	10	25	19	42	32	63	49
11	24	20	41	33	62	50
23	21	40	34	61	51
22	39	35	60	52
38	36	59	53
37	58	54
57	55
56

A221215 as an upper right triangle

1	6	2	15	7	28	16	45	29	66	46	91
	5	3	14	8	27	17	44	30	65	47
		4	13	9	26	18	43	31	64	48
			12	10	25	19	42	32	63	49
				11	24	20	41	33	62	50
					23	21	40	34	61	51
						22	39	35	60	52
							38	36	59	53
								37	58	54
									57	55
										56