210101010

Appears in sequences

• Lexicographically earliest increasing sequence with property that in the concatenation of its terms every pair of consecutive digits differs by 1.at n=33A098766
• The sequence alternates even and odd integers but also even and odd digits; it is monotonically increasing and a(n) is always the smallest integer fitting the pattern.at n=34A137667
• a(0) = 0; thereafter a(n) is the lexicographically earliest missing nonnegative integer such that the digits in the sequence (ignoring the commas) alternate in parity.at n=18A377919