External module "math/base/special/lucas/docs/types/index.d"

Export assignment lucas

• lucas(n: number): number

• Computes the nth Lucas number.

  Notes

  • Lucas numbers follow the recurrence relation L_n = L_{n-1} + L_{n-2} with seed values L_0 = 2 and L_1 = 1.
  • If n is greater than 76, the function returns NaN, as larger Lucas numbers cannot be accurately represented due to limitations of double-precision floating-point format.
  • If not provided a nonnegative integer value, the function returns NaN.

  Parameters

  • n: number

    the Lucas number to compute

  Returns number

  Lucas number

  Example

  var y = lucas( 0 );
  // returns 2

  Example

  var y = lucas( 1 );
  // returns 1

  Example

  var y = lucas( 2 );
  // returns 3

  Example

  var y = lucas( 3 );
  // returns 4

  Example

  var y = lucas( 4 );
  // returns 7

  Example

  var y = lucas( 5 );
  // returns 11

  Example

  var y = lucas( 6 );
  // returns 18

  Example

  var y = lucas( NaN );
  // returns NaN

  Example

  var y = lucas( 3.14 );
  // returns NaN

  Example

  var y = lucas( -1.0 );
  // returns NaN