18940

Appears in sequences

• Expansion of (3 + x^2) / (1 - x)^4.at n=29A037237
• Numbers which are the sum of their proper divisors containing the digit 7.at n=24A059466
• Expansion of c(x(1+2x)), c(x) the g.f. of A000108.at n=8A129147
• Values of x in solutions (x,y,z) to the Diophantine equation x^3-x^2+y^3-y^2=z^3-z^2, with 1<x<y<z.at n=30A138667
• Number of (n+1) X 4 binary arrays with rows and columns in nondecreasing order and with no 2 X 2 subblock sum differing from a horizontal or vertical neighbor subblock sum by more than one.at n=10A184065
• Number of nX5 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 1 1 vertically.at n=7A207679
• Number of nXnXn triangular 0..5 arrays with every horizontal row nondecreasing, first elements of rows nonincreasing, last elements of rows nondecreasing, and every row having the same average value.at n=5A215179
• T(n,k)=Number of nXnXn triangular 0..k arrays with every horizontal row nondecreasing, first elements of rows nonincreasing, last elements of rows nondecreasing, and every row having the same average value.at n=50A215182
• Number of 6X6X6 triangular 0..n arrays with every horizontal row nondecreasing, first elements of rows nonincreasing, last elements of rows nondecreasing, and every row having the same average value.at n=4A215186
• Number of compositions (ordered partitions) of n into 2 or more distinct nonnegative parts.at n=21A216708
• Number of (n+2)X(n+2) 0..3 arrays with every consecutive three elements in every row and column having exactly two distinct values, and in every diagonal and antidiagonal not having exactly two distinct values, and new values 0 upwards introduced in row major order.at n=5A252687
• Number of (n+2) X (6+2) 0..3 arrays with every consecutive three elements in every row and column having exactly two distinct values, and in every diagonal and antidiagonal not having exactly two distinct values, and new values 0 upwards introduced in row major order.at n=5A252693
• Number of terms in the fully expanded n-th derivative of x^(x^x).at n=30A281434
• Numbers m such that psi(x) = phi(m) has a solution while sigma(y) = phi(m) has none.at n=21A291524
• Numbers m such that m^2+1 is prime with (m-1)^2+1 and (m+1)^2+1 semiprimes.at n=33A321795