A000329 Nearest integer to b(n), where b(n) = tan(b(n-1)), b(0) = 1.

1, 2, 75, -1, -1, -2, 1, 2, 31, -1, -2, 29, 1, 5, -6, 1, 1, 3, -1, -1, -1, -1, -1, -9, 1, 1, 1, 2, -2, -35, 0, 0, -1, -1, -1, -1, -1, -1, -2, 1, 1, 1, 5, -1, -2, 4, 1, 2, -4, 0, 0, 0, -1, -1, -1, -1, -1, -1, -2, 1, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1

Offset

0,2

Comments

We have a(11764189) = 329, from b(11764189) ~ 328.86367. This value was found using interval arithmetic with MPFR's tangent function (rounding the results downward and upward at each step), starting at an initial precision of 70000 bits. - Matthew House, Nov 17 2024

Links

Matthew House, Table of n, a(n) for n = 0..10000 (terms 0..1016 from Peter J. Taylor)

Peter J. Taylor, C# program to output a b-file

Mathematica

Round[NestList[Tan, 1, 100]] (* Matthew House, Nov 17 2024 *)

Crossrefs

Cf. A000319.

Sequence in context: A116172 A358383 A238820 * A091978 A282966 A351433

Adjacent sequences: A000326 A000327 A000328 * A000330 A000331 A000332

Keyword

sign

Author

N. J. A. Sloane

Extensions

Terms a(71) and beyond from Peter J. Taylor, Nov 23 2017

Status

approved