2097148

Appears in sequences

• a(n) = 2^n - 4.at n=19A028399
• Sum of terms in row n of A081532.at n=37A081533
• Values of A102370 which are >= a new power of 2.at n=20A103529
• Let S(n)=Sigma(n)/2. Numbers n such that S(S(n))=n, 1/2-Sociable number of order 1 or 2.at n=35A113791
• a(n) = Sum_{k=0..n} floor(C(n,k)/2).at n=22A120739
• Number of pairs of probabilistically independent subsets in a set composed of n elements.at n=19A121312
• Row sums of triangle A166455.at n=20A166456
• Second diagonal under the main diagonal in A172119 written in a square (see comment).at n=19A173033
• Largest members of fully k-sociable cycles of order r.at n=32A183023
• Numbers k such that phi(k) - k = phi(k') - k', where k' is the arithmetic derivative of k and phi(k) is the Euler totient function.at n=28A239940
• Submain diagonal of array A265903: a(n) = A265903(n+1, n).at n=15A265909
• 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 619", based on the 5-celled von Neumann neighborhood.at n=20A283353
• 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 633", based on the 5-celled von Neumann neighborhood.at n=23A283402
• 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 705", based on the 5-celled von Neumann neighborhood.at n=20A283650
• Decimal representation of the diagonal from the corner to the origin of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 705", based on the 5-celled von Neumann neighborhood.at n=20A290194
• Decimal representation of the diagonal from the corner to the origin of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 961", based on the 5-celled von Neumann neighborhood.at n=20A290828
• Number of smallest coverings of the n-dipyramidal graph by maximal cliques.at n=37A298648
• a(n) = 2^n - (2^(n-1) mod n), where "mod" is the nonnegative remainder operator.at n=20A320465
• Numbers that are either already perfect, or a perfect number is eventually reached if we start doubling them.at n=33A341622
• a(n) is the number of times that only 2 pegs have disks on them during the optimal solution to a Towers of Hanoi problem with n disks.at n=38A347789