18321

Appears in sequences

• Main diagonal of Wythoff array: w(n,n)=[ n*tau ]F(n+1)+(n-1)F(n), where tau=(1+sqrt(5))/2, F(n) = Fibonacci numbers.at n=13A020941
• Fibonacci sequence beginning 4,9.at n=17A022130
• Main diagonal of the Stolarsky array.at n=13A035489
• a(n) = 5*n*a(n-1) + 1 with a(0)=1.at n=4A056546
• E.g.f.: exp(8x)/(1-8x)^(1/8).at n=4A094935
• Area of annuli of consecutive integer thickness.at n=17A114378
• Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1000-1000-1100-0111 pattern in any orientation.at n=11A147106
• Number of poly-IH64-tiles (holes allowed) with n cells.at n=9A151525
• Numbers n such that the sum of the prime distinct divisors of n^2+1 equals 2 times the difference between the largest and the smallest prime divisor.at n=5A200071
• Values of x in the solutions to x^2 - 3xy + y^2 + 29 = 0, where 0 < x < y.at n=18A218735
• Numbers m with C(2*m, m) + prime(m) prime, where C(2*m, m) = (2*m)!/(m!)^2.at n=44A236242
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 147", based on the 5-celled von Neumann neighborhood.at n=30A270292
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 961", based on the 5-celled von Neumann neighborhood.at n=23A273833
• a(n) = F(n+1)^4 - 4*F(n-1)*F(n)^3, where F(n) = A000045(n), the n-th Fibonacci number.at n=6A318404
• Rectangular array R read by antidiagonals: R(n,k) = F(n+1)^k - k*F(n-1)*F(n)^(k-1), where F(n) = A000045(n), the n-th Fibonacci number; n >= 0, k >= 1.at n=51A318405
• Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of the e.g.f. exp(x)/(1 - k*x).at n=49A320031
• Numbers k such that usigma(uphi(k)) = uphi(usigma(k)), where usigma is the sum of unitary divisors function (A034448) and uphi is the unitary totient function (A047994).at n=40A329730
• Fixed points of A340069.at n=12A340100
• Number of partitions of n in which exactly one odd part is repeated and even parts are unrestricted.at n=39A353903