21853

Appears in sequences

• Numbers k such that 233*2^k+1 is prime.at n=25A032493
• Expansion of (5 + 3*x + x^2 - x^3) / (1 - 2*x - 2*x^2 - 2*x^3 + x^4) in powers of x.at n=8A071100
• Partial sums of A005578.at n=15A086445
• a(n) = Sum_{k=0..floor(n/2)} binomial(n,2*k)*Fibonacci(k).at n=14A101890
• a(n) = floor(sqrt(a(n-1)^2 + a(n-2)^2)), a(1)=1, a(2)=3.at n=40A104803
• Small-number statistic from the enumeration of domino tilings of a 3-pillow of order n.at n=18A112835
• Numerator of Euler(n,7).at n=5A157835
• a(n) = 12*n^2 - 8*n + 9.at n=42A167585
• Constant term of the reduction by x^2 -> x+1 of the polynomial p(n,x) defined at Comments.at n=17A192960
• Expansion of x * (1 + x) * (1 - x^2) * (1 + x^3) / (1 - 2*x^2 - 2*x^4 - 2*x^6 + x^8) in powers of x.at n=21A206625
• Number of triples (w,x,y) with all terms in {0,...,n} and w < floor((x+y)/3).at n=40A212971
• Primitive values n such that the square with opposite corners (0,0) and (n,n) contains a point (x,y) with integer coordinates, with 0 < x,y < n, at an integer distance from three of the four corners.at n=32A260549
• Number of (n+1) X (2+1) arrays of permutations of 0..n*3+2 with each element having index change +-(.,.) 0,0 0,2 or 1,0.at n=4A264202
• T(n,k)=Number of (n+1)X(k+1) arrays of permutations of 0..(n+1)*(k+1)-1 with each element having index change +-(.,.) 0,0 0,2 or 1,0.at n=19A264207
• Decimal representation of the x-axis, from the origin to the right edge, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 161", based on the 5-celled von Neumann neighborhood.at n=14A279501
• Number of nXn 0..1 arrays with every element unequal to 0, 1 or 2 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=10A317758
• Numbers p^2*q, p > q odd primes such that q does not divide p-1, and q does not divide p+1.at n=37A350421
• Bitwise encoding of the state of a 1D cellular automaton after n steps from ...111000... where adjacent cells swap 01 <-> 10 when within triples 110 or 011.at n=31A359303
• Number of labeled simple graphs covering n vertices and contradicting a strict version of the axiom of choice.at n=6A367868
• Numbers k such that sigma(k) = psi(k) + tau(k) + omega(k)^3.at n=11A392263