72
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119. un = (-n4 + 15n3 - 77n2 + 225n + 192)/6
107 double difference each time 2 + 7 = 9 9 + 7 + 7 = 23 23 + 14 + 14 = 51 51 + 28 + 28 = 107
It could be: 2*214 = 428
77040
Each number is multiplied by an incrementing value. 107 is multiplied by 2, 214 is multiplied by 3, 642 is multiplied by 4 and so on.