18594916

Appears in sequences

• Number of nX2 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 one plus the sum of the elements diagonally to its northwest or zero plus the sum of the elements antidiagonally to its northeast, modulo 4.at n=19A240148
• Expansion of (1/x) * Series_Reversion( x / (1 + x^2 * (1 + x)^2)^2 ).at n=15A389632