A065224 Fill a triangular array by rows by writing numbers 1 up to b(0), 1 up to b(1), etc., where b(n) are the octagonal numbers. The final elements of the rows form a(n).

1, 2, 5, 1, 6, 12, 19, 6, 15, 25, 36, 8, 21, 35, 50, 1, 18, 36, 55, 75, 96, 22, 45, 69, 94, 120, 14, 42, 71, 101, 132, 164, 21, 55, 90, 126, 163, 201, 15, 55, 96, 138, 181, 225, 270, 36, 83, 131, 180, 230, 281, 333, 45, 99, 154, 210, 267, 325, 384, 36, 97, 159, 222