20569

Appears in sequences

• Tetranacci numbers: a(n) = a(n-1) + a(n-2) + a(n-3) + a(n-4) for n >= 4 with a(0) = a(1) = a(2) = 0 and a(3) = 1.at n=19A000078
• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 78 ones.at n=25A031846
• Number of partitions of n into parts not of the form 23k, 23k+11 or 23k-11. Also number of partitions with at most 10 parts of size 1 and differences between parts at distance 10 are greater than 1.at n=38A035999
• Nonprimes in A078447.at n=3A078877
• Least x = a(n) such that sum of common prime divisors (without multiplicity) of sigma(x) and phi(x) equals n, or 0 if such number (apparently) does not exist.at n=29A082056
• Numbers k such that k divides the (k+1)st Lucas number.at n=7A094397
• The number of reachable states in a simple two-player counting game, in which each player starts with the pair (1,1) and one move is to add one of the opponent's numbers to one of your own numbers, but no number can grow above a pre-defined maximum n. The game continues until one of the players has no legal moves left. The winner is the one having the higher sum of his numbers.at n=19A161531
• a(n) = 7*a(n-1) - 23*a(n-2) + 49*a(n-3) - 49*a(n-4) with a(0)=0, a(1)=1, a(2)=7, a(3)=19.at n=11A214525
• Number of ways to reciprocally link elements of an n X 2 array either to themselves or to exactly one horizontal, vertical or antidiagonal neighbor.at n=7A220547
• T(n,k)=Number of ways to reciprocally link elements of an nXk array either to themselves or to exactly one horizontal, vertical or antidiagonal neighbor.at n=37A220553
• T(n,k)=Number of ways to reciprocally link elements of an nXk array either to themselves or to exactly one horizontal, vertical or antidiagonal neighbor.at n=43A220553
• Number T(n,k) of binary words of length n with exactly k (possibly overlapping) occurrences of the subword given by the binary expansion of n; triangle T(n,k), n>=0, read by rows.at n=50A233940
• Number of binary words of length n avoiding the subword given by the binary expansion of n.at n=15A234005
• Modified quadranacci series.at n=49A274759
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=37A300472
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=43A300472
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 2, 3 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=37A300811
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 2, 3 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=43A300811
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 2, 3, 5 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=37A301450
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 2, 3, 5 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=43A301450