The worksheets for World!Of Numbers plate 219:
(my research range is bases 2 <= b <= 12, also both "appending digits to the RIGHT of a number" and "prepending digits to the LEFT of the number")
Appending digits:
Base 2 appending digits 1 (k <= 10000)
Base 3 appending digits 1 (k <= 2500)
Base 3 appending digits 2 (k <= 10000)
Base 4 appending digits 1 (k <= 1484)
Base 4 appending digits 3 (k <= 10000)
Base 5 appending digits 1 (k <= 2125)
Base 5 appending digits 2 (k <= 2793)
Base 5 appending digits 3 (k <= 1650)
Base 5 appending digits 4 (k <= 2719)
Base 6 appending digits 1 (k <= 5000)
Base 6 appending digits 5 (k <= 10000)
Base 7 appending digits 1 (k <= 152)
Base 7 appending digits 2 (k <= 4100)
Base 7 appending digits 3 (k <= 554)
Base 7 appending digits 4 (k <= 2215)
Base 7 appending digits 5 (k <= 178)
Base 7 appending digits 6 (k <= 10000)
Base 8 appending digits 1 (k <= 410)
Base 8 appending digits 3 (k <= 2585)
Base 8 appending digits 5 (k <= 1040)
Base 8 appending digits 7 (k <= 1065)
Base 9 appending digits 1 (k <= 623)
Base 9 appending digits 2 (k <= 775)
Base 9 appending digits 4 (k <= 467)
Base 9 appending digits 5 (k <= 172)
Base 9 appending digits 7 (k <= 766)
Base 9 appending digits 8 (k <=663)
Base 10 appending digits 1 (k <= 370)
Base 10 appending digits 3 (k <= 5000)
Base 10 appending digits 7 (k <= 3125)
Base 10 appending digits 9 (k <= 12500)
Base 11 appending digits 1
Base 11 appending digits 2
Base 11 appending digits 3
Base 11 appending digits 4
Base 11 appending digits 5
Base 11 appending digits 6
Base 11 appending digits 7
Base 11 appending digits 8
Base 11 appending digits 9
Base 11 appending digits X
Base 12 appending digits 1
Base 12 appending digits 5
Base 12 appending digits 7
Base 12 appending digits E
Prepending digits:
Base 2 prepending digits 1 (k <= 4369)
Base 3 prepending digits 1 (k <= 1505)
Base 3 prepending digits 2 (k <= 10000)
Base 4 prepending digits 1 (k <= 1155)
Base 4 prepending digits 2 (k <= 483)
Base 4 prepending digits 3 (k <= 4651)
Base 5 prepending digits 1 (k <= 1121)
Base 5 prepending digits 2 (k <= 1467)
Base 5 prepending digits 3 (k <= 1169)
Base 5 prepending digits 4 (k <= 2073)
Base 6 prepending digits 1
Base 6 prepending digits 2
Base 6 prepending digits 3
Base 6 prepending digits 4
Base 6 prepending digits 5
Base 7 prepending digits 1
Base 7 prepending digits 2
Base 7 prepending digits 3
Base 7 prepending digits 4
Base 7 prepending digits 5
Base 7 prepending digits 6
Base 8 prepending digits 1
Base 8 prepending digits 2
Base 8 prepending digits 3
Base 8 prepending digits 4
Base 8 prepending digits 5
Base 8 prepending digits 6
Base 8 prepending digits 7
Base 9 prepending digits 1
Base 9 prepending digits 2
Base 9 prepending digits 3
Base 9 prepending digits 4
Base 9 prepending digits 5
Base 9 prepending digits 6
Base 9 prepending digits 7
Base 9 prepending digits 8
Base 10 prepending digits 1 (k <= 3125)
Base 10 prepending digits 2 (k <= 1440)
Base 10 prepending digits 3 (k <= 5000)
Base 10 prepending digits 4 (k <= 2117)
Base 10 prepending digits 5 (k <= 1443)
Base 10 prepending digits 6 (k <= 2048)
Base 10 prepending digits 7 (k <= 3511)
Base 10 prepending digits 8 (k <= 1123)
Base 10 prepending digits 9 (k <= 11789)
Base 11 prepending digits 1
Base 11 prepending digits 2
Base 11 prepending digits 3
Base 11 prepending digits 4
Base 11 prepending digits 5
Base 11 prepending digits 6
Base 11 prepending digits 7
Base 11 prepending digits 8
Base 11 prepending digits 9
Base 11 prepending digits X
Base 12 prepending digits 1
Base 12 prepending digits 2
Base 12 prepending digits 3
Base 12 prepending digits 4
Base 12 prepending digits 5
Base 12 prepending digits 6
Base 12 prepending digits 7
Base 12 prepending digits 8
Base 12 prepending digits 9
Base 12 prepending digits X
Base 12 prepending digits E