18031

Appears in sequences

• Second diagonal of A027538.at n=6A027542
• a(n) = a(1) + a(2) + ... + a(n-1) - a(m) for n >= 4, where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n-1 <= 2^(p+1), starting with a(1) = 1, a(2) = 3, and a(3) = 4.at n=15A049929
• Largest proper divisor of the n-th Carmichael number (A002997).at n=18A081703
• Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1000-1100-0111 pattern in any orientation.at n=13A146395
• Numerators of the convergents of the continued fraction for 2^(1/4) - 2^(-1/4), the ordinate of the point of bisection of the arc of the unit lemniscate (x^2 + y^2)^2 = x^2 - y^2 in the first quadrant.at n=9A154745
• a(n) = 784*n - 1.at n=22A158399
• Partial sums of A006899.at n=20A170803
• Partial sums of A000602.at n=16A173289
• Numbers n such that 41#*2^n-1 is prime, where # denotes the primorial, A002110.at n=74A176061
• Sequence defined by the recurrence formula a(n+1)=sum(a(p)*a(n-p)+k,p=0..n)+l for n>=1, with here a(0)=1, a(1)=9, k=-1 and l=-1.at n=6A177184
• Number of binary arrays indicating the locations of trailing edge maxima of a random length-n 0..3 array extended with zeros and convolved with 1,2,2,1.at n=21A222106
• O.g.f.: Sum_{n>=0} n! * x^n / Product_{k=1..n} (1 - n^2*k*x).at n=5A229258
• Number of orbits of Aut(Z^7) as function of the infinity norm n of the representative lattice point of the orbit, when the cardinality of the orbit is equal to 13440.at n=39A266398
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 241", based on the 5-celled von Neumann neighborhood.at n=28A270990
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 654", based on the 5-celled von Neumann neighborhood.at n=38A273332
• Number of nX4 0..1 arrays with every element equal to 2, 3, 5, 6 or 8 king-move adjacent elements, with upper left element zero.at n=10A298891
• Maximally idempotent integers with three or more factors.at n=30A306812
• a(n) = Sum_{k=1..n} sigma_2(k) * floor(n/k).at n=32A356042
• a(n) is the number of inequivalent ways to cut an equilateral triangle with edges of size n into equilateral triangles with integer sides.at n=6A358716