27328

Appears in sequences

• Number of immersions of oriented circle into unoriented sphere with n double points.at n=8A008988
• Maximal elements of pairs of "Super Unitary Amicable Numbers", sorted by their minimal elements.at n=40A045614
• a(n) = sigma(a(n-1)) + phi(a(n-1)), a(1)=3.at n=10A063119
• Number of surviving Collatz residues mod 2^n.at n=20A076227
• Product_{k=0..n} (3^(2k+1)+1).at n=3A085522
• Triangle related to exp(x)*sec(2*x).at n=29A117436
• Number of ways to place 3 nonattacking kings on an n X n toroidal board.at n=7A179404
• Number of arrangements of n+1 nonzero numbers x(i) in -2..2 with the sum of div(x(i),x(i+1)), where div(a,b)=a/b produces the integer quotient implying a nonnegative remainder, equal to zero.at n=7A190064
• T(n,k)=Number of arrangements of n+1 nonzero numbers x(i) in -k..k with the sum of div(x(i),x(i+1)), where div(a,b)=a/b produces the integer quotient implying a nonnegative remainder, equal to zero.at n=43A190071
• Number of arrangements of 9 nonzero numbers x(i) in -n..n with the sum of div(x(i),x(i+1)), where div(a,b)=a/b produces the integer quotient implying a nonnegative remainder, equal to zero.at n=1A190078
• Number of 2 X 2 matrices with all elements in {0,1,...,n} and determinant >= 2n.at n=16A210367
• Triangle read by rows: T(n,g) = number of general immersions of a circle with n crossings in a surface of arbitrary genus g (the circle is oriented, the surface is unoriented).at n=28A260885
• Numbers n such that A003146(n) = floor(alpha^3*n)+1, where alpha = 1.839... is the positive real zero of x^3-x^2-x-1.at n=27A278353
• Relative of Hofstadter Q-sequence: a(n) = max(0, n+27298) for n <= 0; a(n) = a(n-a(n-1)) + a(n-a(n-2)) + a(n-a(n-3)) for n > 0.at n=31A283888
• Positions of records in A375202.at n=20A375203