A065226 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 decagonal numbers. The final elements of the rows form a(n).
1, 2, 5, 9, 4, 10, 17, 25, 7, 17, 28, 40, 1, 15, 30, 46, 63, 81, 15, 35, 56, 78, 101, 125, 24, 50, 77, 105, 134, 164, 20, 52, 85, 119, 154, 190, 227, 33, 72, 112, 153, 195, 238, 282, 30, 76, 123, 171, 220, 270, 321, 3, 56, 110, 165, 221, 278, 336, 395, 4, 65, 127, 190
Offset: 0