257115

Appears in sequences

• Least positive integer k such that the fractional part of k*sqrt(5) has its n initial partial quotients all equal to 1.at n=12A004794
• a(n) = C(n-1,1) + C(n-3,3) + ... + C(n-2*m-1,2*m+1), where m = floor((n-2)/4).at n=26A024490
• a(n) = floor((Fibonacci(2*n+1)+1)/2).at n=14A087953
• Expansion of (1+x)/((1+x+x^2)(1-x-x^2)).at n=27A093040
• Row sums of triangle A099510, so that a(n) = Sum_{k=0..n} coefficient of z^k in (1 + 2*z + z^2)^(n-[k/2]), where [k/2] is the integer floor of k/2.at n=13A099511
• Expansion of g.f. (1+x)^2/((1 + x + x^2)*(1 + x - x^2)).at n=30A106511
• a(n) = floor[(phi + n mod 2)*a(n-1)], a(1)=1.at n=19A107857
• a(n) = b(k), where b(k) = Fibonacci(n-1) and k = floor( n*(1+sqrt(5))/2 ).at n=19A107858
• Number of nonnegative even integers <= Fibonacci(n).at n=29A147997
• a(n) = ceiling(Fibonacci(n)/2).at n=29A173173
• a(n) = (A000045(n)+A173432(n))/2.at n=28A173433
• a(2k) = floor(F(k)/2), a(2k+1) = ceiling(F(k)/2), where F = A000045 is the Fibonacci sequence.at n=59A173673
• a(n) = A174618(n) + A174618(n+1).at n=53A174619
• a(n) = (Fibonacci(3*n-1) + 1)/2 for n >= 1.at n=9A292278
• Numbers k such that the k-th centered 40-gonal numbers (A195317) is a square.at n=9A351354