-1
domain: Z
Appears in sequences
- Expansion of e.g.f. exp(-2*x)/(1-x).at n=1A000023
- Ménage numbers: a(0) = 1, a(1) = -1, and for n >= 2, a(n) = number of permutations s of [0, ..., n-1] such that s(i) != i and s(i) != i+1 (mod n) for all i.at n=1A000179
- Nearest integer to tan n.at n=12A000209
- Nearest integer to tan n.at n=15A000209
- Nearest integer to tan n.at n=18A000209
- Nearest integer to tan n.at n=34A000209
- Nearest integer to tan n.at n=37A000209
- Nearest integer to tan n.at n=40A000209
- Nearest integer to tan n.at n=43A000209
- Nearest integer to tan n.at n=56A000209
- Nearest integer to tan n.at n=59A000209
- Nearest integer to tan n.at n=62A000209
- Nearest integer to tan n.at n=65A000209
- Nearest integer to tan n.at n=78A000209
- Nearest integer to tan n.at n=81A000209
- a(n) = floor(b(n)), where b(n) = tan(b(n-1)), b(0)=1.at n=3A000319
- a(n) = floor(b(n)), where b(n) = tan(b(n-1)), b(0)=1.at n=18A000319
- a(n) = floor(b(n)), where b(n) = tan(b(n-1)), b(0)=1.at n=19A000319
- a(n) = floor(b(n)), where b(n) = tan(b(n-1)), b(0)=1.at n=20A000319
- a(n) = floor(b(n)), where b(n) = tan(b(n-1)), b(0)=1.at n=21A000319