A317387 Square array T(n, k) read by antidiagonals upwards, n > 0 and k > 0: T(n, k) is the least positive multiple of n that contains k as a substring in its decimal representation.
1, 10, 2, 12, 2, 3, 12, 12, 30, 4, 10, 12, 3, 4, 5, 12, 20, 32, 24, 50, 6, 14, 12, 30, 4, 15, 6, 7, 16, 21, 30, 40, 52, 6, 70, 8, 18, 24, 35, 24, 5, 16, 27, 8, 9, 10, 27, 32, 14, 54, 60, 72, 18, 90, 10, 11, 20, 36, 24, 35, 6, 70, 8, 9, 10, 11, 12, 22, 30, 45
Offset: 1
Examples
Array T(n, k) begins:
n\k| 1 2 3 4 5 6 7 8 9 10 11 12
---+------------------------------------------------------------
1| 1 2 3 4 5 6 7 8 9 10 11 12
2| 10 2 30 4 50 6 70 8 90 10 110 12
3| 12 12 3 24 15 6 27 18 9 102 111 12
4| 12 12 32 4 52 16 72 8 92 100 112 12
5| 10 20 30 40 5 60 70 80 90 10 110 120
6| 12 12 30 24 54 6 72 18 90 102 114 12
7| 14 21 35 14 35 56 7 28 49 105 112 112
8| 16 24 32 24 56 16 72 8 96 104 112 112
9| 18 27 36 45 45 36 27 18 9 108 117 126
10| 10 20 30 40 50 60 70 80 90 10 110 120
Programs
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PARI
T(n, k, base=10) = { my (w=base^#digits(k, base)); for (m=1, oo, my (mn=m*n); while (mn >= k, if (mn % w == k, return (m*n), mn \= base))) }