A070748 a(n) = signum(sin(prime(n))), where signum=A057427, prime=A000040.

1, 1, -1, 1, -1, 1, -1, 1, -1, -1, -1, -1, -1, -1, 1, 1, 1, -1, -1, 1, -1, -1, 1, 1, 1, 1, 1, 1, 1, -1, 1, -1, -1, 1, -1, 1, -1, -1, -1, -1, 1, -1, 1, -1, 1, -1, -1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, 1, 1, -1, 1, -1, -1, 1, -1, 1, -1, -1, 1, -1, 1, 1, 1

Offset: 1

Author

Reinhard Zumkeller, May 04 2002

Keywords

• sign

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A070747, A070750, A070749, A070753, A070754.

Programs

Mathematica

Sign[Sin[Prime[Range[10000]]]] (* Andrey Mitin, Apr 22 2022 *)

PARI

a(n)=(-1)^(prime(n)/Pi%2\1) \\ Charles R Greathouse IV, Jun 13 2013