1010101

Appears in sequences

• Numbers whose square is a palindrome.at n=40A002778
• Rows of Sierpiński's triangle (Pascal's triangle mod 2).at n=6A006943
• Representation of n in base of Fibonacci numbers (the Zeckendorf representation of n). Also, binary words starting with 1 not containing 11, with the word 0 added.at n=33A014417
• Divisors of 99999999.at n=41A027890
• Numbers k such that k^2 is a palindrome with an odd number of digits.at n=38A028816
• a(n) = 1(01)^(2*n+1).at n=1A031982
• Sums of 4 distinct powers of 10.at n=20A038446
• Numbers whose base-10 representation has exactly 7 runs.at n=0A043643
• Alternate digits 1 and 0.at n=7A056830
• Palindromes whose square is a palindrome; also palindromes whose sum of squares of digits is less than 10.at n=30A057135
• Palindromes only using 0 and 1 (i.e., base-2 palindromes).at n=17A057148
• a(n) = n^6 + n^4 + n^2 + 1.at n=10A059830
• Palindromes that are the sum of two shorter palindromes.at n=27A062696
• Carryless binary square of n; also Moser-de Bruijn sequence written in binary.at n=15A063010
• Positions of positive coefficients in cyclotomic polynomial Phi_n(x), A063696 in binary.at n=14A063697
• Working in base 2, replace n with the concatenation of its prime divisors in increasing order.at n=19A064841
• Palindromes whose digit sum is 4.at n=13A065983
• Sum_{k=1..n, gcd(n,k) = 1} 10^(k-1).at n=6A073030
• a(1) = 1, a(n) = smallest palindrome not included earlier such that a(1)+...+a(n) is a palindrome.at n=44A073880
• Numbers of the form (10^(m*r)-1)/(10^r-1) for positive integers m, r.at n=13A076289