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A173261 as a triangular array

1
12
131
1412
15131
161412
1715131
18161412
191715131
11018161412
111191715131
11211018161412
113111191715131
11411211018161412

A173261 as a square array

11111111111111
234567891011121314
111111111111
23456789101112
1111111111
2345678910
11111111
2345678
111111
23456
1111
234
11
2
11111111111111
234567891011121314
111111111111
23456789101112
1111111111
2345678910
11111111
2345678
111111
23456
1111
234
11
2