1000002

Appears in sequences

• Numbers written in base of triangular numbers.at n=29A000462
• Lexicographically earliest strictly increasing base 3 autovarious sequence: a(n) = number of distinct a(k) mod 3^n (written in base 3).at n=30A037091
• Lexicographically earliest strictly increasing base 5 autovarious sequence: a(n) = number of distinct a(k) mod 5^n (written in base 5).at n=27A038114
• Lexicographically earliest strictly increasing base 6 autovarious sequence: a(n) = number of distinct a(k) mod 6^n (written in base 6).at n=20A038115
• Numbers whose square contains the same digit more than 2/3 of the time and does not end in 0.at n=16A039820
• Integers k < (reversal of k) such that (reversal of k) + 1 is divisible by k-1.at n=7A052148
• Numbers k such that 10^k == -1 (mod k-1).at n=6A055693
• Numbers k such that k^2 contains only digits {0,1,4}, not ending with zero.at n=20A058413
• Suburban numbers: without b, r, s or u.at n=37A072955
• Urban numbers: without 'r' or 'u'.at n=65A072957
• Smallest k such that the concatenation 123...(k-1) k (k-1)...321 ( a concatenation of natural numbers from 1 to k and back to 1) is a multiple of prime(n), or 0 if no such number exists.at n=14A077187
• a(1) = 2, then the smallest squarefree number greater than the previous term that begins with the end of the previous term.at n=15A077209
• Minimal (positive) solution a(n) of Pell equation a(n)^2 - D(n)*b(n)^2 = +4 with D(n)= A077425(n). The companion sequence is b(n)=A078355(n).at n=17A077428
• Triangle, read by rows, in which the n-th row contains n smallest n-digit numbers.at n=23A081551
• 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=17A098752
• Admirable Harshad numbers such that the subtracted divisor is also a Harshad number.at n=31A109396
• Numbers k such that k concatenated with k-6 gives the product of two numbers which differ by 5.at n=19A116118
• Smallest k such that the concatenation from 1 to k and back to 1 is divisible by 2n-1, or 0 if no such k exists.at n=23A120008
• Numbers with n 0's between 1 and 2.at n=5A133384
• a(n+1) is the least integer > a(n) containing all digits of a(n); a(1)=2.at n=31A155890