ASTACK

[Xlambda]

ASTACK stacks an array, calls AUNSTACK

=LAMBDA(a,w,
    LET(k,ABS(w),
       IF(k>=COLUMNS(a),a,TRANSPOSE(AUNSTACK(TRANSPOSE(a),k)))
    )
)

LAMBDA 5.0.xlsx
	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P	Q	R	S
1	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18
2	19	20	21	22	23	24	25	26	27	28	29	30	31	32	33	34	35	36
3	37	38	39	40	41	42	43	44	45	46	47	48	49	50	51	52	53	54
4
5
6		6	1	2	3	4	5	6		5	1	2	3	4	5
7			19	20	21	22	23	24			19	20	21	22	23
8			37	38	39	40	41	42			37	38	39	40	41
9			7	8	9	10	11	12			6	7	8	9	10
10			25	26	27	28	29	30			24	25	26	27	28
11			43	44	45	46	47	48			42	43	44	45	46
12			13	14	15	16	17	18			11	12	13	14	15
13			31	32	33	34	35	36			29	30	31	32	33
14			49	50	51	52	53	54			47	48	49	50	51
15											16	17	18
16											34	35	36
17											52	53	54
18
Sheet6

Cell Formulas
Range	Formula
A1:R3	A1	=SEQUENCE(3,18)
C6:H14	C6	=ASTACK(A1#,B6)
K6:O17	K6	=ASTACK(A1#,J6)
Dynamic array formulas.