131313

Appears in sequences

• Positive numbers k such that k and 2*k are anagrams in base 5 (written in base 5).at n=24A023061
• Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 1,3.at n=5A037582
• First number of height n in Recamán's sequence A005132.at n=21A064290
• Values of A005132(n) at which the ratio A005132(n)/n sets a new record.at n=12A064621
• Triplets: base 10 representation is the juxtaposition of three identical strings.at n=12A074842
• Concatenate the terms of three copies of the Fibonacci sequence.at n=7A134554
• a(n) = 13*(100^(n+1) - 1)/99.at n=2A156641
• List of imprimitive words over the alphabet {1,3}.at n=13A213973
• List of words over {1,3} with equal numbers of 1's and 3's.at n=13A214488
• Non-primitive words on {1,2,3}.at n=26A239018
• After a(1) = 1, the sequence is always extended with the smallest divisor d (not yet present in the sequence) of the last term t. If d doesn't exist, we extend the sequence with tt (t concatenated to itself). If tt doesn't produce a new d, we extend the sequence with ttt, etc. See the Comments section for more details.at n=22A348871