42660

Appears in sequences

• E-trees with exactly 2 colors.at n=9A007143
• At stage 1, start with a unit square. At each successive stage add 4*(n-1) new squares around outside with edge-to-edge contacts. Sequence gives number of squares (regardless of size) at n-th stage.at n=39A056640
• Number of squares in the interior of the square with vertices (n,0), (0,n), (-n,0) and (0,-n) in a square (x,y)-grid.at n=39A111746
• Triangle read by rows: T(n,k) is number of Motzkin paths of length n having k UH's, where U=(1,1), H=(1,0) (0<=k<=floor(n/3)).at n=42A114576
• E.g.f. satisfies: A(x) = (1 + x*A(x))^(A(x)^2).at n=5A162656
• Number of -n..n arrays x(0..3) of 4 elements with zero sum and nonzero first and second differences.at n=19A200456
• Number of (w,x,y) with all terms in {0,...,n} and the numbers w,x,y,|w-x|,|x-y|,|y-w| distinct.at n=38A213493
• 100-gonal numbers: a(n) = 98*n*(n-1)/2 + n.at n=30A261276
• a(n) = n! * [x^n] exp(n*x)*arcsinh(x).at n=6A302606
• Array read by descending antidiagonals: A(n,k) is the number of oriented colorings of the edges of a regular n-dimensional simplex using up to k colors.at n=25A327083
• Exponential (2,4)-perfect numbers: numbers m such that esigma(esigma(m)) = 4m, where esigma(m) is the sum of exponential divisors of m (A051377).at n=20A328133
• Number of integer partitions of n with more than one non-mode.at n=41A363124