123456

Appears in sequences

• Concatenations of cyclic permutations of initial positive integers.at n=15A001292
• Blocks of increasing length using 1,2,3,...,9,10; omit leading 0's.at n=6A001369
• Triangle of the gods: to get a(n), concatenate the decimal numbers 1,2,3,...,n.at n=5A007908
• a(0) = 0; for n>0, a(n) = 10*a(n-1) + n.at n=6A014824
• Positive numbers k such that k and 5*k are anagrams in base 7 (written in base 7).at n=10A023071
• Smallest number that contains the numbers from 1 to n as substrings.at n=5A035239
• Concatenate next digit at right hand end (where the next digit after 9 is again 0).at n=6A057137
• a(n) = floor(10^(n+1)/81).at n=6A057932
• Numbers in which each digit is the (immediate) successor of the previous one (if it exists) and 0 is considered the successor of 9.at n=46A059043
• String together the first n numbers in an order which minimizes the result.at n=5A060555
• Smallest number that begins with 1, has digits in order 123...901... and is divisible by n. If no such number exists then a(n) = 0.at n=7A061074
• Smallest number that begins with 1, has digits in order 123...901... and is divisible by n. If no such number exists then a(n) = 0.at n=15A061074
• a(n) is the concatenation of the phi(n) numbers between 1 and n that are relatively prime to n.at n=6A061097
• Numbers k such that (i) k is a concatenation of consecutive natural numbers starting at 1 and (ii) k+1 is prime.at n=2A069048
• Terms of A007908 which are divisible by their index.at n=4A071269
• Smallest multiple of n which begins with the concatenation of first n natural numbers.at n=5A074158
• Partition the concatenation 1234567...of natural numbers into successive strings which are multiples of 8, all different and > 8. (0 never taken as the most significant digit.)at n=0A077301
• Smallest multiple of n formed by the concatenation of n successive numbers, or 0 if no such number exists.at n=5A077306
• In the following triangle the n-th row contains n n-digit (or (n-1)-digit) numbers whose concatenation (with a 0 prefixed for (n-1)-digit numbers) gives a substring of the cyclic concatenation of 1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9,0,1,2,...: 1; 12 34; 123 456 789; 1234 5678 9012 3456; 12345 67890 12345 67890 12345; ... Sequence contains the final terms of rows.at n=5A078193
• In the following triangle the n-th row contains n n-digit (or (n-1)-digit) numbers whose concatenation (with a 0 prefixed for (n-1)-digit numbers) gives a substring of the cyclic concatenation of 1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9,0,1,2,...: 1; 12 34; 123 456 789; 1234 5678 9012 3456; 12345 67890 12345 67890 12345; ... Sequence contains the triangle by rows.at n=15A078194