Pascal's Triangle
- Each number is equal to the sum of the two numbers above it.
- Each row of numbers symmetrically by 1 is gradually increased.
- Digital line n has n items.
- Number m of n-th row may be represented as C (n-1, m-1), that is, taking the number of combinations m-1 elements different from the n-1 elements.
- The number m of the n-th row and the n-m + 1 number equal to the number one combination of properties.
- Each digit equal to the previous line and about two numbers. This property can be used to write the entire Pascal's Triangle. I.e. the n + 1 i-th row is equal to the number of i-1 and i-th and the n-th row sum, one of which is a combination of several properties. I.e., C (n + 1, i) = C (n, i) + C (n, i-1).
- (A + b) Expanding the factor n in the corresponding sequence of (n + 1) Pascal's triangle in each row.
- The first number 2n + 1 of the first row, the second with 2n + 2 number of the third row, the row number of 2n + 3 ...... 5 in a line, and the first of these numbers 4n + 1 th Fibonacci lease number; the first row of the second number 2n (n> 1), with the first 2n-1 number of row 4, line number 2n-2 6 ...... sum of these first and 4n-2 th Fei the number of waves that deed.
- The number n-th row are multiplied by 10 ^ (m-1), wherein the number of columns m for is located, and then added to the 11 ^ (n-1). 11 ^ 0 = 1,11 ^ 1 = 1x10 ^ 0 + 1 × 10 ^ 1 = 11,11 ^ 2 = 1 × 10 ^ 0 + 2x10 ^ 1 + 1x10 ^ 2 = 121,11 ^ 3 = 1x10 ^ 0 + 3 × 10 ^ 1 + 3x10 ^ 2 + 1x10 ^ 3 = 1331,11 ^ 4 = 1x10 ^ 0 + 4x10 ^ 1 + 6x10 ^ 2 + 4x10 ^ 3 + 1x10 ^ 4 = 14641,11 ^ 5 = 1x10 ^ 0 + 5x10 ^ 1 + 10x10 ^ 2 + 10x10 ^ 3 + 5x10 ^ 4 + 1 × 10 ^ 5 = 161051.
- and n is the row number 2 ^ (n-1). 1 = ^ 2 (1-0), 1 + 1 = 2 ^ (2-1), 1 + 2 + 1 = ^ 2 (3-1), 3 + 3 + 1 + 1 = 2 ^ (4-1 ), 1 + 4 + 6 + 4 + 1 = ^ 2 (5-1), 1 + 5 + 10 + 10 + 5 + 1 = ^ 2 (6-1).
- Any of a number equal to the diagonal upper right corner thereof, the numbers on the corners. 1 + 2, 1 + 1 = 1 + 1 + 1 = 3,1 + 4,1 + 1 + 1 = 2 + 3,1 = 6,1 = 2 + 3 + 2 + 3 + 4 = + 10,1 3 = 3 + 4,1 + 6 + 4 = 10, 1 = 5.
- The numbers to the left of each row are aligned, which top right to bottom left diagonal equal Fibonacci numbers Fibonacci sequence of digital data. 1, 1 + 1 = 2, 2 + 1 = 3 + 1 = 3,1 + 5,3 + 8,1 + 4 + 1 = 5 + 1 = 6 + 10 + 6 + 13, 4 + 1 = 21,1 + 7 + 10 + 15 + 20 + 1 = 34,5 + 21 + 8 + 1 = 55.
/**
* 打印杨辉三角
* 是 二项式系数 在三角形中的一种几何排序
*/
public function test()
{
echo "<pre>";
$arr = [];
$N = 10; //打印几层
for($i = 0; $i<$N; $i++) { //几层
for($m = 0;$m<$N-$i;$m++) {
print_r(' ');
}
for($j = 0; $j<=$i; $j++)
{
if((0 == $j)||($i == $j)){
$arr[$i][$j] = 1;
}else{
$arr[$i][$j] = $arr[$i-1][$j] + $arr[$i-1][$j-1];
}
print_r($arr[$i][$j]);
}
print_r("\n");
}
}