-987

Appears in sequences

• a(1) = 0, a(2) = -2; for n > 2, a(n) + a(n-2) - a(n-3) - a(n-5) - ... - a(n-p) = (-1)^(n+1)*n if n is prime, otherwise = 0, where p = largest prime < n.at n=46A002120
• Triangle of Lehmer-Comtet numbers of the first kind.at n=50A008296
• a(n+2) = -a(n+1) + a(n) (signed Fibonacci numbers) with a(-2) = a(-1) = 1; or Fibonacci numbers (A000045) extended to negative indices.at n=18A039834
• a(n) = (-1)^(n-1)*(a(n-1) - a(n-2)), a(1)=1, a(2)=1.at n=34A051792
• a(n) = (-1)^(n-1)*(a(n-1) - a(n-2)), a(1)=1, a(2)=1.at n=37A051792
• A measure of how close the golden ratio is to rational numbers.at n=20A066212
• A measure of how close the golden ratio is to rational numbers.at n=41A066212
• Expansion of 1/( (1-x)*(1 + x^2 + x^3) ).at n=43A077889
• Expansion of (1-x)^(-1)/(1+2*x+x^2-x^3).at n=21A077929
• Expansion of (-3*x^3-18*x^2+14*x-1)/(3*x^4-5*x^2+4*x-1).at n=18A103135
• A transform of the Fibonacci numbers.at n=16A103311
• A transform of the Fibonacci numbers.at n=17A103311
• Expansion of (1-x)*(1-x+x^2)/(1-3*x+4*x^2-2*x^3+x^4).at n=15A105371
• Expansion of (x-1)*(x+1) / (8*x^2 + 1 - 3*x + x^4 - 3*x^3).at n=7A108196
• A characteristic triangle for the Fibonacci numbers.at n=43A110033
• First differences of A135992.at n=16A135994
• Binomial transform of 1, 1, 0, -1, -1 (periodically continued).at n=15A138003
• Fibonacci numbers (A000045) starting at offset -20.at n=4A147316
• a(n) = a(n-1)+a(n-2), n>1 ; a(0)=1, a(1)=-1.at n=18A152163
• a(n)=Product_{k=1..floor((n-1)/2)} (1 + 4*cos(k*Pi/n)^2)*(1 - 4*sin(k*Pi/n)^2).at n=16A152191