From the infinite triangular array of positive integers, suppose we select every 2nd numbers on every 2nd row as shown below:

$$
\underline{1} \\
\;2\; \quad \;3\; \\
\;\underline{4}\; \quad \;5\; \quad \;\underline{6}\; \\
\;7\; \quad \;8\; \quad \;9\; \quad 10 \\
\underline{11} \quad 12 \quad \underline{13} \quad 14 \quad \underline{15} \\
16 \quad 17 \quad 18 \quad 19 \quad 20 \quad 21 \\
\underline{22} \quad 23 \quad \underline{24} \quad 25 \quad \underline{26} \quad 27 \quad \underline{28} \\
\cdots
$$

The resulting sequence ([A185868](http://oeis.org/A185868)) is as follows:

```
1, 4, 6, 11, 13, 15, 22, 24, 26, 28, 37, 39, 41, 43, 45, 56, 58, 60, 62, 64, 66,
79, 81, 83, 85, 87, 89, 91, 106, 108, 110, 112, 114, 116, 118, 120, 137, ...

```

The task is to output this sequence.

[sequence](/questions/tagged/sequence "show questions tagged 'sequence'") I/O rules apply. You can choose to implement one of the following:

* Given the index \$n\$ (0- or 1-based), output the \$n\$th term of the sequence.
* Given a positive integer \$n\$, output the first \$n\$ terms of the sequence.
* Take no input and output the entire sequence by
	+ printing infinitely or
	+ returning a lazy list or a generator.

Standard [code-golf](/questions/tagged/code-golf "show questions tagged 'code-golf'") rules apply. The shortest code in bytes wins.