1212121212

Appears in sequences

• Two-bell analog of A028355.at n=14A028359
• Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 1,2.at n=9A037487
• a(n) is the smallest number not already present that permits the cyclic repetition of the path 1,2 of the digits in the sequence.at n=18A165300
• a(n) = a(n-1) + 12*100^(n-1), with a(0)=0.at n=5A177090