a(n) in base n is the concatenation of the base n expansions of (1, 2, 3, ..., n-1, n, n-1, ..., 3, 2, 1).
A260851
a(n) in base n is the concatenation of the base n expansions of (1, 2, 3, ..., n-1, n, n-1, ..., 3, 2, 1).
Terms
- a(0) =1a(1) =13a(2) =439a(3) =27961a(4) =3034961a(5) =522134761a(6) =131870760799
External references
- oeis: A260851