**Triangle where the k-th item at n-th row (both starting from 1) tells in how many ways we can add 2 distinct integers from 1 to n, in such way that the sum is divisible by k.**

*0, 1, 0, 3, 1, 1, 6, 2, 2, 1, 10, 4, 4, 2, 2, 15, 6, 5, 3, 3, 2, 21, 9, 7, 5, 4, 3, 3, 28, 12, 10*

*2 seqfan posts*

Index of A-numbers in seqfan: by ascending order by month by frequency by keyword

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