-212

Appears in sequences

• Discriminants of quadratic number fields Q(sqrt -n) for n squarefree.at n=32A033197
• Matrix 8th power of inverse partition triangle A038498.at n=28A050311
• Matrix inverse of triangle A055340(n+1,k).at n=40A055347
• Binomial transform of pentanacci numbers A074048: a(n)=Sum((-1)^k*Binomial(n,k)*A074048(k),(k=0,..,n)).at n=9A075194
• E.g.f.: exp(-exp(-x)+1+x).at n=10A109747
• Semiprime(n)*semiprime(n+3) - semiprime(n+1)*semiprime(n+2), where semiprime(n) is the n-th semiprime.at n=9A118780
• Matrix inverse of triangle A121336, where A121336(n,k) = C( n*(n+1)/2 + n-k + 2, n-k) for n>=k>=0.at n=24A121441
• Irregular triangle formed by coefficients of polynomials defined by P(n,k,x) = f(n,k)*(2*x)^k*(1 - x^2)^(n - k), where f(n, k) = (-1)^floor((k + 1)/2)* binomial(n - floor((k + 1)/2), floor(k/2)).at n=41A123218
• Inverse of Fibonacci convolution array A154929.at n=24A154930
• First differences of A072272.at n=15A170878
• a(0) = -1 and a(n) = (-1)^(n+1)*(3*n^2 - n + 4)/2 for n >= 1.at n=12A173247
• Array: row n shows the coefficients of the characteristic polynomial of the n-th principal submatrix of A203945.at n=40A203946
• Array: row n shows the coefficients of the characteristic polynomial of the n-th principal submatrix of M (as in A204026), given by min(F(i+1),F(j+1)), where F=A000045 (Fibonacci numbers).at n=21A204027
• Array: row n shows the coefficients of the characteristic polynomial of the n-th principal submatrix of f(i,j)=max(ceiling(i/j),ceiling(j/i)) (as in A204143).at n=36A204144
• Choose smallest m>0 such that the n-th rational prime p ramifies in the imaginary quadratic extension field K = Q(sqrt(-m)); a(n) = discriminant(K).at n=15A220861
• First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 139", based on the 5-celled von Neumann neighborhood.at n=9A270281
• First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 222", based on the 5-celled von Neumann neighborhood.at n=36A270941
• First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 243", based on the 5-celled von Neumann neighborhood.at n=9A271003
• First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 251", based on the 5-celled von Neumann neighborhood.at n=9A271019
• First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 262", based on the 5-celled von Neumann neighborhood.at n=21A271068