378999

Appears in sequences

• Number of (n+1)X(n+1) 0..2 arrays with diagonal zero and the i,j-th 2X2 subblock sum equal to the j,i-th 2X2 subblock sum.at n=3A187402
• T(n,k)=Number of (n+1)X(n+1) 0..k arrays with diagonal zero and the i,j-th 2X2 subblock sum equal to the j,i-th 2X2 subblock sum.at n=13A187408
• Numbers that require exactly 8 iterations to determine that they are happy or not (A007770 and A031177).at n=28A193996