Problem Eleven

eleven.js

var grid = [ 08,02,22,97,38,15,00,40,00,75,04,05,07,78,52,12,50,77,91,08,49,49,99,40,17,81,18,57,60,87,17,40,98,43,69,48,04,56,62,00,81,49,31,73,55,79,14,29,93,71,40,67,53,88,30,03,49,13,36,65,52,70,95,23,04,60,11,42,69,24,68,56,01,32,56,71,37,02,36,91,22,31,16,71,51,67,63,89,41,92,36,54,22,40,40,28,66,33,13,80,24,47,32,60,99,03,45,02,44,75,33,53,78,36,84,20,35,17,12,50,32,98,81,28,64,23,67,10,26,38,40,67,59,54,70,66,18,38,64,70,67,26,20,68,02,62,12,20,95,63,94,39,63,08,40,91,66,49,94,21,24,55,58,05,66,73,99,26,97,17,78,78,96,83,14,88,34,89,63,72,21,36,23,09,75,00,76,44,20,45,35,14,00,61,33,97,34,31,33,95,78,17,53,28,22,75,31,67,15,94,03,80,04,62,16,14,09,53,56,92,16,39,05,42,96,35,31,47,55,58,88,24,00,17,54,24,36,29,85,57,86,56,00,48,35,71,89,07,05,44,44,37,44,60,21,58,51,54,17,58,19,80,81,68,05,94,47,69,28,73,92,13,86,52,17,77,04,89,55,40,04,52,08,83,97,35,99,16,07,97,57,32,16,26,26,79,33,27,98,66,88,36,68,87,57,62,20,72,03,46,33,67,46,55,12,32,63,93,53,69,04,42,16,73,38,25,39,11,24,94,72,18,08,46,29,32,40,62,76,36,20,69,36,41,72,30,23,88,34,62,99,69,82,67,59,85,74,04,36,16,20,73,35,29,78,31,90,01,74,31,49,71,48,86,81,16,23,57,05,54,01,70,54,71,83,51,54,69,16,92,33,48,61,43,52,01,89,19,67,48 ],
    largest = 0,
    sequence = [ [ -21, -42, -63 ], [ -20, -30, -40 ], [ -19, -38, -57 ], [ 1, 2, 3 ], [ 21, 42, 63 ], [ 20, 30, 40 ], [ 19, 38, 57 ], [ -1, -2, -3 ] ];
    current = 0;

for ( var i = 0; i < grid.length; i++ ) {
    
    for ( var j = 0; j < sequence.length; j++ ) {
        
        current = grid[ i ];
        
        for ( var k = 0; k < sequence[ j ].length; k++ )
            if ( grid[ i + sequence[ j ][ k ] ] === undefined )
                break;
            else
                current = current * grid[ i + sequence[ j ][ k ] ];
        
    
        if ( current > largest )
            largest = current;

    }; 

};

document.write( largest );