Dash*, 69 bytes

seq -- -8 8|xargs -I: sh -c 'seq -s"`printf "%:s_"`" 10'|sed s/_1*//g

Hopefully this iteration is fairly self explanatory -- pretty much a straight swap of for to xargs.

Try it online!

Dash*, (削除) 87 (削除ここまで), (削除) 86 (削除ここまで), 73 bytes

for p in `seq -- -8 8`;do seq -s"`printf "%${p}s_"`" 10;done|sed s/_1*//g

Try it online!

Explanation

for p in `seq -- -8 8`

Produce -8 to 8, used to create separator in next seq. NB BusyBox’s seq barfs on the -8 without the -- but TIO’s Dash env does not.

;do seq -s"`printf "%${p}s_"`" 10

Print 1-10, separated with p ×ばつ spaces, with an extra _ appended (because seq won't accept an empty separator).

;done|sed s/_1*//g

Remove the _ as well as the 1 from trailing 10.

EDIT: removed a silly space (thanks Kevin Cruijssen)

EDIT: saved many bytes because negative padding printf doesn't matter

EDIT: scraped off another few bytes by ditching the for in favour of xargs.

_{*Actually this is aimed at Busybox 1.31.1 ash, sed, seq and printf, but TIO didn't have that environment. NB available seq options are pretty minimal.}

Dash*, 69 bytes

seq -- -8 8|xargs -I: sh -c 'seq -s"`printf "%:s_"`" 10'|sed s/_1*//g

Hopefully this iteration is fairly self explanatory -- pretty much a straight swap of for to xargs.

Try it online!

Dash*, (削除) 87 (削除ここまで), (削除) 86 (削除ここまで), 73 bytes

for p in `seq -- -8 8`;do seq -s"`printf "%${p}s_"`" 10;done|sed s/_1*//g

Try it online!

Explanation (for method)

for p in `seq -- -8 8`

Produce -8 to 8, used to create separator in next seq. NB BusyBox’s* seq barfs on the -8 without the -- but TIO’s Dash env does not.

;do seq -s"`printf "%${p}s_"`" 10

Print 1-10, separated with p ×ばつ spaces, with an extra _ appended (because seq won't accept an empty separator).

;done|sed s/_1*//g

Remove the _ as well as the 1 from trailing 10.

EDIT: removed a silly space (thanks Kevin Cruijssen)

EDIT: saved many bytes because negative padding printf doesn't matter

EDIT: scraped off another few bytes by ditching the for in favour of xargs.

_{*Actually this is aimed at Busybox 1.31.1 ash, sed, seq and printf, but TIO didn't have that environment. NB available seq options are limited to -w and -s.}

Dash*, (削除) 87 (削除ここまで), (削除) 86 (削除ここまで), 73 bytes

_{*Actually this is aimed at Busybox 1.31.1 ash, sed, seq and printf, but TIO didn't have that environment. NB available seq options are pretty minimal.}

for p in `seq -- -8 8`;do seq -s"`printf "%${p}s_"`" 10;done|sed s/_1*//g

Try it online!

Explanation

for p in `seq -- -8 8`

Produce -8 to 8, used to create separator in next seq. NB BusyBox’s seq barfs on the -8 without the -- but TIO’s Dash env does not.

;do seq -s"`printf "%${p}s_"`" 10

Print 1-10, separated with p ×ばつ spaces, with an extra _ appended (because seq won't accept an empty separator).

;done|sed s/_1*//g

Remove the _ as well as the 1 from trailing 10.

EDIT: removed a silly space (thanks Kevin Cruijssen)

EDIT: saved many bytes because negative padding printf doesn't matter

Dash*, 69 bytes

seq -- -8 8|xargs -I: sh -c 'seq -s"`printf "%:s_"`" 10'|sed s/_1*//g

Hopefully this iteration is fairly self explanatory -- pretty much a straight swap of for to xargs.

Try it online!

Dash *, (削除) 87 (削除ここまで), (削除) 86 (削除ここまで), 73 bytes

for p in `seq -- -8 8`;do seq -s"`printf "%${p}s_"`" 10;done|sed s/_1*//g

Try it online!

Explanation

for p in `seq -- -8 8`

Produce -8 to 8, used to create separator in next seq. NB BusyBox’s seq barfs on the -8 without the -- but TIO’s Dash env does not.

;do seq -s"`printf "%${p}s_"`" 10

Print 1-10, separated with p ×ばつ spaces, with an extra _ appended (because seq won't accept an empty separator).

;done|sed s/_1*//g

Remove the _ as well as the 1 from trailing 10.

EDIT: removed a silly space (thanks Kevin Cruijssen)

EDIT: saved many bytes because negative padding printf doesn't matter

EDIT: scraped off another few bytes by ditching the for in favour of xargs.

_{*Actually this is aimed at Busybox 1.31.1 ash, sed, seq and printf, but TIO didn't have that environment. NB available seq options are pretty minimal.}

Dash*, (削除) 87 (削除ここまで), (削除) 86 (削除ここまで), 73 bytes

_{*Actually this is aimed at Busybox 1.31.1 ash, sed, seq and printf, but TIO didn't have that environment. NB available seq options are pretty minimal.}

for p in `seq -- -8 8`;do seq -s"`printf "%${p}s_"`" 10;done|sed s/_1*//g

Try it online!

Explanation

for p in `seq -- -8 8`

Produce -8 to 8, used to create separator in next seq. NB BusyBox’s seq barfs on the -8 without the -- but TIO’s Dash env does not.

;do seq -s"`printf "%${p}s_"`" 10

Print 1-10, separated with p ×ばつ spaces, with an extra _ appended (because seq won't accept an empty separator).

;done|sed s/_1*//g

Remove the _ as well as the 1 from trailing 10.

EDIT: removed a silly space (thanks Kevin Cruijssen) *EDIT: saved many bytes because negative padding printf works fine.

Dash*, (削除) 87 (削除ここまで), (削除) 86 (削除ここまで), 73 bytes

_{*Actually this is aimed at Busybox 1.31.1 ash, sed, seq and printf, but TIO didn't have that environment. NB available seq options are pretty minimal.}

for p in `seq -- -8 8`;do seq -s"`printf "%${p}s_"`" 10;done|sed s/_1*//g

Try it online!

Explanation

for p in `seq -- -8 8`

Produce -8 to 8, used to create separator in next seq. NB BusyBox’s seq barfs on the -8 without the -- but TIO’s Dash env does not.

;do seq -s"`printf "%${p}s_"`" 10

Print 1-10, separated with p ×ばつ spaces, with an extra _ appended (because seq won't accept an empty separator).

;done|sed s/_1*//g

Remove the _ as well as the 1 from trailing 10.

EDIT: removed a silly space (thanks Kevin Cruijssen)

EDIT: saved many bytes because negative padding printf doesn't matter