2088960

Appears in sequences

• Number of subsets of {1,..,n} containing at least one prime.at n=20A089820
• Numbers n such that sigma(uphi(n)) = n where uphi is the unitary totient (or unitary phi) function (see A047994).at n=33A120116
• Expansion of 1/(8*x^5+8*x^4-8*x^3-4*x^2+1).at n=18A123959
• Triangle read by rows: T(n,k) is the number of permutations p of {1,2,...,n} for which the number of j < ceiling(n/2) such that p(j) + p(n+1-j) = n+1 is equal to k (n>=1; 0<=k <=ceiling(n/2)).at n=34A155517
• Number of permutations p of {1,2,...,n} such that p(j) + p(n+1-j) != n+1 for all j.at n=10A155518
• Number of permutations p of 1,2,...,n satisfying |p(i+5)-p(i)|<>5 for all 1<=i<=n-5.at n=9A189256
• Number of ways to place n nonattacking composite pieces rook + rider[5,5] on an n X n chessboard.at n=9A189841
• a(0)=1, a(1)=0, a(n) = 4*n*(n-1)*(a(n-1) + 2*(n-1)*a(n-2)).at n=5A189849
• Arises in enumerating Huffman codes, compact trees, and sums of unit fractions.at n=23A194633
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 139", based on the 5-celled von Neumann neighborhood.at n=20A286025
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 179", based on the 5-celled von Neumann neighborhood.at n=20A286207
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 187", based on the 5-celled von Neumann neighborhood.at n=20A286502
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 209", based on the 5-celled von Neumann neighborhood.at n=20A286701
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 814", based on the 5-celled von Neumann neighborhood.at n=20A286866
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 251", based on the 5-celled von Neumann neighborhood.at n=20A287189
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 422", based on the 5-celled von Neumann neighborhood.at n=20A288125
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 467", based on the 5-celled von Neumann neighborhood.at n=20A288442
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 505", based on the 5-celled von Neumann neighborhood.at n=20A288771
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 507", based on the 5-celled von Neumann neighborhood.at n=20A288804
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 878", based on the 5-celled von Neumann neighborhood.at n=20A290659