3131313131

Appears in sequences

• Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 3,1.at n=9A037589
• Concatenation of segments of the digit sequence 1 3 1 3 1 3 1 3 1 3 1 3 1 3 1 3 1 3....at n=9A137318