A000290The squares: a(n) = n^2.

0, 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, 196, 225, …

The first 6 terms appear at position 16,685,566.

…40079633254351355110636301491625817096558747523350862759…
position 16,685,566
termsstringfirst positionoccurrences
103299,993,942
2011679,998,250
3014669998,307
401493,13499,556
5014916160,006919
60149162516,685,56614
70149162536not within 1,000,000,0000
8014916253649not within 1,000,000,0000

Searched the first 1,000,000,000 digits. Strings longer than 12 digits are not indexed.