51384

Appears in sequences

• Number of 3 X n grids of black and white cells, no 3 of same color vertically or horizontally contiguous.at n=7A060521
• a(n) = 2^n - A143658(n).at n=17A101836
• Number of (n+2)X8 binary arrays avoiding patterns 000 and 111 in rows and columns.at n=0A203405
• T(n,k)=Number of (n+2)X(k+2) binary arrays avoiding patterns 000 and 111 in rows and columns.at n=15A203407
• T(n,k)=Number of (n+2)X(k+2) binary arrays avoiding patterns 000 and 111 in rows and columns.at n=20A203407
• T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 1 0 and 1 0 1 vertically.at n=47A207808
• T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 0 and 1 0 1 vertically.at n=47A208028
• T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 1 1 0 vertically.at n=47A208287
• T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 0 and 0 1 1 vertically.at n=47A208420
• E.g.f.: S(x) = Sum_{n>=0} sinh((2*n+1)*x) * x^n / (1 - x^(2*n+1)).at n=5A257215
• Expansion of g.f. A(x) satisfying Sum_{n>=0} Product_{k=1..n} (x^k + 3*A(x)) = 1 + 4*Sum_{n>=1} x^(n*(n+1)/2).at n=8A370143
• Numbers k such that (k*2^d - 1)*(d*2^k - 1) is semiprime for some divisor d of k.at n=51A382646