41698

Appears in sequences

• Number of n X n arrays of squares of integers with every (n-1)X(n-1) subblock summing to 6 and every element equal to at least one neighbor.at n=3A146198
• Coefficients in the expansion of ([s] + [2s]x + [3s]x^2 + ...)/([r] + [2r]x + [3r]x^2 + ...); [ ] = floor, r = sqrt(3), s = r/(1-r).at n=40A279630
• Expansion of Product_{i>=1, j>=1} (1 + x^(i*j*(j + 1)/2)).at n=48A327745
• a(n) is the least integer k such that n/(Sum_{j=1..n} 1/phi(k*j)) is an integer.at n=27A341813