19450

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has period 47.at n=26A020386
• Number of (1,1) steps starting at level zero in all peakless Motzkin paths of length n+3.at n=11A089737
• Number of compositions (ordered partitions) of n with designated summands.at n=13A091601
• Triangle read by rows: T(n,k) (0 <= k <= ceiling(n/2)-2) is the number of (1,1) steps starting at level k in all peakless Motzkin paths of length n (can be easily translated into RNA secondary structure terminology).at n=36A110238
• Expansion of x*(8*x^5 + 5*x^4 - x^3 - 5*x^2 - 1)/(x^6 + 3*x^5 + 6*x^4 + 4*x^3 - 5*x^2 + x - 1).at n=15A122607
• Numbers n such that 6*p(n)-1 and 6*p(n)+1 are twin primes and 6*p(n+1)-1 and 6*p(n+1)+1 are also twin primes with p(n) = n-th prime.at n=26A126655
• a(n) is the number of regular D classes in the semigroup of all binary relations on [n].at n=8A173311
• Number of (n+1) X 2 binary arrays with no 2 X 2 subblock determinant equal to any horizontal or vertical neighbor 2 X 2 subblock determinant.at n=8A185459
• T(n,k)=Number of (n+1)X(k+1) binary arrays with no 2X2 subblock determinant equal to any horizontal or vertical neighbor 2X2 subblock determinant.at n=36A185467
• Triangle, read by rows, such that row n equals the coefficients of x^(n^2+n-1+k) in F(x,n) for k = 1..n, where F(x,n) = (1 + x*F(x,n))*(1 + x^n/F(x,n)), for n>=1.at n=37A200171
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 181", based on the 5-celled von Neumann neighborhood.at n=30A270628
• E.g.f. C = C(x,y) satisfies: A^2 + B^2 + C^2 = 1 + y^2 and A^3 + B^3 + C^3 = 1 + y^3, where functions A = A(x,y) and B = B(x,y) are described by A278885 and A278886, respectively.at n=92A278887
• Decimal representation of the x-axis, from the left edge to the origin, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 246", based on the 5-celled von Neumann neighborhood.at n=14A280331
• Numbers k such that sopfr((k-1)!) is divisible by k, where sopfr(k) = A001414(k) = sum of primes, with repetition, dividing k.at n=11A343424