20671

Appears in sequences

• Numerators of continued fraction convergents to sqrt(277).at n=7A041520
• Number of scalene triangles, distinct up to congruence, on an n X n grid (or geoboard).at n=18A190313
• Numbers of ways in which a unit disc can be dissected into 6n curvilinear triangles, at least one of which does not contain the center.at n=29A193362
• Numbers n such that n!8-2 is prime.at n=55A204664
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 459", based on the 5-celled von Neumann neighborhood.at n=31A272289
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 603", based on the 5-celled von Neumann neighborhood.at n=26A273173
• a(n) = Sum_{k=1..n} sigma(n*k).at n=28A372710
• a(0) = 2, thereafter a(n+1) is the nearest integer to 4*a(n)/3.at n=32A390254