A321351 a(n) is the index of the row of A321350 in which n first appears, or zero if n does not appear.
0, 1, 0, 26, 3, 0, 19, 5, 0, 21, 7, 0, 23, 9, 0, 25, 11, 0, 27, 13, 0, 29, 15, 0, 2, 17, 0, 4, 19, 0, 6, 21, 0, 8, 23, 0, 10, 25, 0, 12, 27, 0, 14, 29, 0, 16, 31, 0, 18, 33, 0, 20, 35, 0, 22
Offset: 1
Examples
a(5) = 3, since in A321350, 2 --> (2+3)^2 --> 5, so 5 first appears in the third row.
Formula
a(n) <= (2/3)*n + 15 for n > 6.
Comments