-859

Appears in sequences

• For all n >= 2, Sum_{2<=k<=n, gcd(k,n)>1} a(k) = n. a(1)=1.at n=59A124386
• Triangle T(n,k), n>=1, 0<=k<=n^2, read by rows: row n gives the coefficients of the chromatic polynomial of the square diagonal grid graph DG_(n,n), highest powers first.at n=10A212208
• First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 425", based on the 5-celled von Neumann neighborhood.at n=21A272092
• First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 489", based on the 5-celled von Neumann neighborhood.at n=21A272513
• Expansion of 1/(Sum_{i>=0} q^(i^2)/Product_{j=1..i} (1 - q^j + q^(2*j))).at n=45A294598