200001

Appears in sequences

• Numbers k equal to the number of 1's in the decimal digits of all numbers <= k.at n=13A014778
• Numbers k such that k^2+k+2 is a palindrome.at n=26A027712
• Lexicographically earliest strictly increasing base 4 autovarious sequence: a(n) = number of distinct a(k) mod 4^n (written in base 4).at n=34A038113
• Lexicographically earliest strictly increasing base 5 autovarious sequence: a(n) = number of distinct a(k) mod 5^n (written in base 5).at n=24A038114
• Numbers whose square contains the same digit more than 2/3 of the time and does not end in 0.at n=11A039820
• Numbers k such that k^2 contains only digits {0,1,4}, not ending with zero.at n=16A058413
• Automorphic numbers: numbers k such that k^6 ends with k. Also m-morphic numbers for all m not congruent to 26 (mod 50) but congruent to 6 (mod 10).at n=43A068408
• a(1) = 2, then the smallest squarefree number greater than the previous term that begins with the end of the previous term.at n=13A077209
• Least m ending in 1 such that m^n ends in a string of n 0's followed by the final 1.at n=4A085610
• Let P(i) = i-th prime. To get a(n), factor P(n)-1 as a product of primes, then concatenate the exponents.at n=15A097463
• a(1) = 1 and a(n+1) is the least number > a(n) that begins with the last digit of a(n) and doesn't end with 0.at n=15A098752
• a(n+1) is the least integer > a(n) containing all digits of a(n); a(1)=2.at n=26A155890
• Numbers n with property that average digit of n^2 is less than 1.at n=13A164842
• Sum of any three adjacent digits of n^2 is a square.at n=41A174397
• Cantor's ordering of positive rational numbers, where a(n) is the balanced ternary representation of the "factorization" of the positive rational number into terms of A186285.at n=46A185169
• a(n) = 2*10^n + 1.at n=5A199682
• Numbers k such that the number of times digit 'm' used for writing the decimal representation between 1 to k is equal to k for at least one value of m in the range m = 1 to 9.at n=13A216400
• Numbers k such that 3*R_k + 50 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=24A256800
• Numbers n such that sum of decimal digits of n equals number of prime divisors of n counted with multiplicity and sum of distinct decimal digits of n equals number of distinct primes dividing n.at n=21A280911
• List of binary words of lengths 0, 1, 2, etc., including empty word, each prefixed by a 2.at n=32A319953