1001001001

Appears in sequences

• Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 1,0,0.at n=9A033146
• Palindromes whose digit sum is 4.at n=26A065983
• Numbers of the form (10^(m*r)-1)/(10^r-1) for positive integers m, r.at n=22A076289
• Palindromes of the form n^3 + n^2 + n + 1.at n=5A086143
• Palindromes i such that 2*i^2 is a palindrome.at n=29A256495
• a(n) = Sum_{k=0..n} 1000^k.at n=3A261544
• Binary representation of the diagonal from the corner to the origin of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 846", based on the 5-celled von Neumann neighborhood.at n=32A290552
• Palindromes of even length only using 0 or 1.at n=18A342036