201201

Appears in sequences

• Lucky numbers that are concatenations of a number k with itself.at n=25A032650
• Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 2,0,1.at n=5A037519
• Pseudoprimes to base 6, written in base 6.at n=34A262103
• Ternary numbers that are concatenated runs C(1)B(1)A(1)C(2)B(2)A(2)...C(k)B(k)A(k), where A(i) is a run of 1's, B(i) a run of 0's, and C(i) a run of 2's, for i = 1..k.at n=14A371109