1231231

Properties

Appears in sequences

• Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 1,2,3.at n=6A037610
• Primes of the form 30030*p + 1 where p is a prime.at n=5A051651
• A triangle sequence based on a prime root product using a primorial function: f(n)=primorial(n); p(x,n)=If[n == 0, 1, f(n)*(x + 1/f(n))*Product[x + Prime[i], {i, 1, n - 1}]]; t(n,m)=coefficients(p(x,n)).at n=34A142583
• a(n) is the smallest number not already in the sequence, such that the concatenation of all a(n) displays the periodic digit string 1, 2, 3 (and repeat).at n=16A165301
• Primes formed by concatenating k, k, and 1 for k >= 1.at n=33A210511
• Periodic primes: primes p whose decimal expansion can be written as sss...st, where s is nonempty string of digits not beginning with 0, there are at least two copies of s, and t (which may be absent) is a prefix of s.at n=16A232066
• Prime numbersat n=95137