-87
domain: Z
Appears in sequences
- a(n) = a(n-1) - 2*a(n-2) with a(0) = 2, a(1) = 1.at n=14A002249
- Coefficients of the '2nd-order' mock theta function mu(q).at n=48A006306
- Expansion of (eta(q) * eta(q^2) * eta(q^3) * eta(q^6))^2 in powers of q.at n=48A030209
- Discriminants of quadratic number fields Q(sqrt -n) for n squarefree.at n=54A033197
- Triangle formed from expansion of (x-1)*(x+2)*(x-3)*...*(x+-n).at n=24A047991
- a(n) = (a(n-1)*a(n-3) - a(n-2)^2) / a(n-4), with a(0) = 0, a(1) = a(2) = a(3) = 1, a(4) = -1.at n=12A050512
- Start with 0, run through primes >=5, adding if -1 mod 6, subtracting if +1 mod 6.at n=45A051356
- a(n) = Sum_{i=n-4..n-1} (-1)^i*a(i), a(1)=1, a(2)=1, a(3)=1, a(4)=1.at n=46A051793
- a(n) = Sum_{i=n-4..n-1} (-1)^i*a(i), a(1)=1, a(2)=1, a(3)=1, a(4)=1.at n=51A051793
- a(n) = Sum_{d|2n+1} phi(d)*mu(d).at n=44A054586
- n - reversal of base 4 digits of n (written in base 10).at n=74A055949
- Hankel transform of partition numbers (A000041).at n=66A056223
- Low-temperature magnetization expansion for Kagome net (Potts model, q=3).at n=8A057398
- Differences between the primes generating the n-th prime power.at n=48A068389
- Years of recorded observations of Comet Halley.at n=2A072235
- Expansion of (1-x)^(-1)/(1+x-2*x^2+x^3).at n=7A077899
- Expansion of (1-x)^(-1)/(1+2*x-2*x^2).at n=5A077917
- Expansion of 1/(1-x-x^2+2*x^3).at n=21A077948
- Expansion of (1-x)/(1+2*x^2-x^3).at n=12A078035
- 4th differences of partition numbers A000041.at n=61A081094