18016

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 67.at n=28A031565
• Numerators of continued fraction convergents to sqrt(245).at n=7A041458
• Index values for new maxima in A065925.at n=19A065926
• Numbers useful in computing A(k), the largest possible magnitude of the x^k coefficient in a cyclotomic polynomial.at n=4A140671
• a(n) = ((4+sqrt(5))*(2+sqrt(5))^n + (4-sqrt(5))*(2-sqrt(5))^n)/2.at n=6A163070
• G.f.: exp( Sum_{n>=1} A174476(n)*x^n/n ) where A174476(n) = Sum_{d|n} d^phi(d).at n=8A174475
• Number of 4-step left-handed knight's tours (moves only out two, left one) on an n X n board summed over all starting positions.at n=25A187174
• Stack polyominoes with square core.at n=44A188674
• a(n) = Sum_{i=0..n} digsum_5(i)^4, where digsum_5(i) = A053824(i).at n=31A231671
• Values of x such that x^2 = 5*y^2 + 11, where x and y are positive integers.at n=6A281064
• O.g.f. A(x) satisfies: [x^n] exp( n^2 * A(x) ) = n^3 * [x^(n-1)] exp( n^2 * A(x) ) for n>=1.at n=3A300593
• Number of even parts in the partitions of n into 10 parts.at n=41A309662
• a(0) = 0, a(1) = 1, for n > 1, a(n) = 2^(n+1) - 3*(sigma((2^n)-1) - sigma((2^(n-1))-1)).at n=13A329892
• Consider the figure made up of a row of n adjacent congruent rectangles, with diagonals of all possible rectangles drawn; a(n) is the number of interior vertices where exactly four lines cross.at n=44A336490
• Number of essentially series oriented series-parallel networks with n elements and without multiple unit elements in parallel.at n=11A339288