20805

Appears in sequences

• Base-4 digits are, in order, the first n terms of the periodic sequence with initial period 1,1,0.at n=7A033131
• One-dimensional cellular automaton 'sigma' (Rule 150).at n=14A038185
• Base-8 palindromes that start with 5.at n=23A043025
• Numbers k such that 165*2^k-1 is prime.at n=49A050834
• Integers k such that k*28*c + 1 is prime for c = 1, 2, 4, 7 and 14.at n=10A067199
• Expansion of 1/(1-x+2*x^2+x^3).at n=22A077955
• Expansion of 1/(1+x+2*x^2-x^3).at n=22A077978
• Expansion of g.f. -(1+x^2+x^4)/((x^3+x^2+x-1)*(x-1)^2).at n=14A104187
• The n-th n-gonal number divisible by n.at n=14A117669
• Recurrence sequence derived from the digits of the square root of 3 after its decimal point.at n=6A120482
• Half the number of length n integer sequences with sum zero and sum of squares 288.at n=4A157544
• Let a(0) = a(1) = 1, and n*a(n) = 2*(-7+5*n)*a(n-1) + 9*(2-n)*a(n-2) for n >= 2.at n=7A162326
• Let b(n) be the n-th positive integer that is a palindrome in base 2. a(n) = the smallest multiple of b(n) that is > b(n) and that is also a palindrome in binary.at n=36A162843
• Let y = y(u,v) be implicitly defined by g(u,v,y(u,v)) = 0. Read as a triangle by rows, the sequence represents the number of terms a(i,k-i) in the expansion of the bivariate divided difference [u_0,...,u_i; v_0,...,v_{k-i}]y in terms of trivariate divided differences of g.at n=34A172003
• Let y = y(u,v) be implicitly defined by g(u,v,y(u,v)) = 0. Read as a triangle by rows, the sequence represents the number of terms a(i,k-i) in the expansion of the bivariate divided difference [u_0,...,u_i; v_0,...,v_{k-i}]y in terms of trivariate divided differences of g.at n=27A172003
• Numbers whose sum of triangular divisors is also a divisor and greater than 1.at n=27A209311
• Numbers n palindromic in exactly three bases b, 2 <= b <= 10.at n=44A214425
• -3-Knödel numbers.at n=29A225507
• Triangle with first column identical to 1 and the other entries defined by the sum of entries above and to the left.at n=35A226392
• Palindromic numbers in bases 2 and 8 written in base 10.at n=43A259380