Look-and-say数列是一个有趣的数列。有关介绍参见维基百科的。在OEIS网站上，数列号为。

这个程序打印输出Look-and-say数列的前18项。

C语言程序如下：

/* I00031 Look-and-say sequence */#include 
    
     #include 
     
      #define MAXN 100000char s[MAXN+1], t[MAXN+1];char *ps, *pt;int main(void){    char look;    int say, i;    memset(s, 0, sizeof(s));    memset(t, 0, sizeof(t));    s[0] = '1';    for(i=0; i<18; i++) {        if(i & 1) {            ps = t;            pt = s;        } else {            ps = s;            pt = t;        }        printf("%s\n", ps);        look = *ps;        say = 1;        while(*(++ps)) {            if(*ps == look)                say++;            else {                *pt++ = '0' + say;                *pt++ = look;                look = *ps;                say = 1;            }        }        *pt++ = '0' + say;        *pt++ = look;    }    return 0;}
     
    

运行结果如下：

1

11

21

1211

111221

312211

13112221

1113213211

31131211131221

13211311123113112211

11131221133112132113212221

3113112221232112111312211312113211

1321132132111213122112311311222113111221131221

11131221131211131231121113112221121321132132211331222113112211

311311222113111231131112132112311321322112111312211312111322212311322113212221

132113213221133112132113311211131221121321131211132221123113112221131112311332111213211322211312113211

11131221131211132221232112111312212321123113112221121113122113111231133221121321132132211331121321231231121113122113322113111221131221

31131122211311123113321112131221123113112211121312211213211321322112311311222113311213212322211211131221131211132221232112111312111213111213211231131122212322211331222113112211