21804

Appears in sequences

• Numbers k such that k + sum of its prime factors = (k+1) + sum of its prime factors.at n=28A020700
• Indices n of primes p(n), p(n+4) such that p(n)-1 and p(n+4)-1 have the same largest prime factor.at n=22A105407
• a(n) = n*(14*n + 13) + 3.at n=39A195029
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 203", based on the 5-celled von Neumann neighborhood.at n=31A270727
• Iterations at which Langton's Ant living on triangular tiling reaches the distance of n from the origin for the first time.at n=39A275303
• Expansion of Product_{k>=0} 1/(1 + x^(3*k+1))^(3*k+1).at n=36A285286
• Number of nX3 0..1 arrays with every element equal to 0, 2, 3, 4, 5 or 6 king-move adjacent elements, with upper left element zero.at n=6A299055
• Number of n X 7 0..1 arrays with every element equal to 0, 2, 3, 4, 5 or 6 king-move adjacent elements, with upper left element zero.at n=2A299059
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 2, 3, 4, 5 or 6 king-move adjacent elements, with upper left element zero.at n=38A299060
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 2, 3, 4, 5 or 6 king-move adjacent elements, with upper left element zero.at n=42A299060
• Numbers k such that s(k) = s(k+1), where s(k) is A059975.at n=13A327250
• Number of isomorphism classes of indecomposable Fano Bott manifolds of complex dimension n.at n=10A345955
• E.g.f. satisfies A(x) = 1 + A(x)^3 * log(1 + x).at n=5A367155
• Expansion of e.g.f. 1/(1 - x + log(1 - 3*x)/3).at n=5A367852