A383858 Irregular triangle read by rows: T(n,k) (n >= 4, 4 <= k <= A384502(n)) is the smallest n-digit number m with k distinct prime factors, such that these factors can be divided into two subsets of at least two elements each, both summing to the same value. If no such number exists, T(n,k) = -1.
2145, 2310, 10725, 10374, 101065, 100050, 255255, 510510, 1005993, 1000350, 1036035, 1009470, 10006081, 10000130, 10012065, 10004610, 100010225, 100001300, 100001195, 100009910, 111546435, 223092870, 1000083889, 1000008758, 1000001751, 1000005270, 1002569295, 1001110110
Offset: 4
Examples
T(4,4) = 2145 = 3*5*11*13 is the smallest four-digit number with four distinct prime factors (3, 5, 11, and 13), where the prime factors can be partitioned into two subsets of at least two elements each, both summing to the same value: 3+13 = 5+11. T(5,4) = 2310 = 2*3*5*7*11 is the smallest five-digit number with four distinct prime factors (2, 3, 5, 7 and 11), where the prime factors can be partitioned into two subsets of at least two elements each, both summing to the same value: 3+11 = 2+5+7. The lower triangle begins at T(4,4): [ 2145, 2310]; [ 10725, 10374]; [ 101065, 100050, 255255, 510510]; [ 1005993, 1000350, 1036035, 1009470]; [ 10006081, 10000130, 10012065, 10004610]; [100010225, 100001300, 100001195, 100009910, 111546435, 223092870]; ...
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