# Fibonacci Number > Maximum safe nth [Fibonacci number][fibonacci-number] when stored in [double-precision floating-point][ieee754] format.
## Usage ```javascript var FLOAT64_MAX_SAFE_NTH_FIBONACCI = require( '@stdlib/constants/float64/max-safe-nth-fibonacci' ); ``` #### FLOAT64_MAX_SAFE_NTH_FIBONACCI The maximum [safe][safe-integers] nth [Fibonacci number][fibonacci-number] when stored in [double-precision floating-point][ieee754] format. ```javascript var bool = ( FLOAT64_MAX_SAFE_NTH_FIBONACCI === 78 ); // returns true ```
## Examples ```javascript var FLOAT64_MAX_SAFE_NTH_FIBONACCI = require( '@stdlib/constants/float64/max-safe-nth-fibonacci' ); var v; var i; function fibonacci( n ) { var a; var b; var c; var i; a = 1; b = 1; for ( i = 3; i <= n; i++ ) { c = a + b; a = b; b = c; } return b; } for ( i = 0; i < 100; i++ ) { v = fibonacci( i ); if ( i > FLOAT64_MAX_SAFE_NTH_FIBONACCI ) { console.log( 'Unsafe: %d', v ); } else { console.log( 'Safe: %d', v ); } } ```