-1908

Appears in sequences

• a(n) = -n^2 - n + 72.at n=44A110678
• Let M be a diagonal matrix with A007442 on the diagonal and P = Pascal's triangle as an infinite lower triangular matrix. Now read the triangle P*M by rows.at n=52A124800
• a(n) = 2*a(n-1) + a(n-2) - 2*a(n-3) - a(n-4) for n>3, a(0)=a(1)=a(3)=0, a(2)=1.at n=17A240847
• Difference between sums of quadratic residues and non-residues modulo n (residues are not necessarily coprime to n).at n=71A255644
• First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 189", based on the 5-celled von Neumann neighborhood.at n=23A270680