21473

Appears in sequences

• a(n) = [ a(n-1)/a(1) ] + [ a(n-2)/a(2) ] + ... + [ a(1)/a(n-1) ], for n >= 3.at n=22A022864
• Primitive subsequence of A111105.at n=35A137559
• 1/12 the number of (n+2)X5 0..2 arrays with each 3X3 subblock containing three of each value.at n=3A184380
• 1/12 the number of (n+2)X6 0..2 arrays with each 3X3 subblock containing three of each value.at n=2A184381
• T(n,k)=1/12 the number of (n+2)X(k+2) 0..2 arrays with each 3X3 subblock containing three of each value.at n=17A184386
• T(n,k)=1/12 the number of (n+2)X(k+2) 0..2 arrays with each 3X3 subblock containing three of each value.at n=18A184386
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 475", based on the 5-celled von Neumann neighborhood.at n=30A272449
• Composite hypotenuses of primitive Pythagorean triangles (A120961) that are not circumdiameters of non-Pythagorean primitive Heronian triangles (A285579).at n=30A329148