20690

Appears in sequences

• a(n) = Sum_{i=0..n} T(i,n-i), array T as in A048149.at n=33A049712
• Antidiagonal triangular matrices of factorials as the example: M(3)={{0, 0, 1}, {0, 1, 2}, {1, 2, 6}}; the matrices are used to get characteristic polynomials and the triangular sequence is the coefficients of those characteristic polynomials.at n=37A137296
• Number of nX4 0..3 arrays with no element equal to one plus the sum of elements to its left or one plus the sum of elements above it or zero plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.at n=6A241431
• T(n,k)=Number of nXk 0..3 arrays with no element equal to one plus the sum of elements to its left or one plus the sum of the elements above it or zero plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.at n=51A241435
• Number of 7Xn 0..3 arrays with no element equal to one plus the sum of elements to its left or one plus the sum of the elements above it or zero plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.at n=3A241441
• Number of (n+1) X (5+1) 0..1 arrays with every 2 X 2 subblock antidiagonal maximum minus diagonal minimum nondecreasing horizontally and diagonal maximum minus antidiagonal minimum nondecreasing vertically.at n=21A253394
• Number of binary strings of length n avoiding 4-antipowers.at n=31A275061
• Number of integer partitions of n with unimodal run-lengths.at n=39A332280
• a(n) = Sum_{k=0..n} binomial(n,k) * binomial((k+1)^2, n).at n=4A346183