54321

Appears in sequences

• Concatenation of numbers from n down to 1.at n=4A000422
• Number of zeros in numbers 1 to 111...1 (n+1 digits).at n=4A014925
• n written in fractional base 6/5.at n=25A024638
• 1+2n+3n^2+4n^3+5n^4.at n=10A056579
• Add (n mod 10)*10^(n-1) to the previous term, with a(0) = 0.at n=5A057138
• String together the first n numbers in an order which maximizes the result.at n=4A060554
• Numbers k such that phi(k)+sigma(k) is a perfect cube.at n=34A061366
• Numbers where k-th digit from right is either 0 or k.at n=31A063013
• Self-conjugate digitized partition numbers.at n=21A068325
• Dealing cards in a game of solitaire.at n=15A071761
• Triangle read by rows: the n-th row contains n numbers sorted in decreasing value, each build by dropping a different number from the sequence [n,n-1,n-2,....,1] and concatenating the n-1 others. By definition the first row contains 0.at n=20A081541
• Concatenation of digits of natural numbers from n down to 1.at n=4A104759
• Numbers with 5 distinct digits {1,2,3,4,5} such that all adjacent digits (as well as first and last digits) are coprime.at n=59A104972
• Integers written in base "triangle".at n=15A110301
• Largest composite number obtained by concatenation of parts of a distinct partition of n, or 0 if no such number exist.at n=14A110454
• Factorial codes for the fixed points of the square of Vaillé's 1997 bijection on Dyck paths.at n=10A126299
• Nonnegative numbers with digits in descending order that differ exactly by 1.at n=35A138142
• a(n) = concatenation of reversed digits of natural numbers from n down to 1.at n=4A138793
• Start with 0; then add one to each single digit.at n=41A158699
• Reverse (palindrome) of A164844.at n=25A168647