1.2.4.7. ().16.22 write the number according to the rule

The second number is larger than the first number by 1,1 + 1 = 2
The third number is 2 larger than the second number, 2 + 2 = 4
The fourth number is larger than the third number by 3,4 + 3 = 7
The fifth number is larger than the fourth number by 4,7 + 4 = (11)
The sixth number is 5 larger than the fifth number, 11 + 5 = 16
The seventh number is larger than the sixth number by 6,16 + 6 = 22

RELATED INFORMATIONS

1. Observe this series of regular numbers: 1 / 2, 1 / 6, 1 / 12, 1 / 30, 1 / 42, and know what the nth number is according to the law
2. Observe the following equations, find the laws from them, and use them to find the values of the following equations Look at the following equations: 1/√2+1=√2-1,1/√3-√2,1/√4-√3,1/√5+√4=√5-√4,… Find the laws from the above equations and use them to find the values of the following equations 1/√2+1+1/√3+√2+1/√4+√3+…… +1/√2013+√2012
3. 32-12=8×1；52-32=8×2；72-52=8×3… Observe the above formula, what law can you find? Please use algebra to express, and use this law to calculate the value of 20012-19992
4. Carefully observe the rules of the following group of formulas and write two such formulas: 99-27 = 72, 88-35 = 53, 77-25 = 52, 55-23 = 32
5. Observe the following three groups of formulas, find the rules and fill in the blanks 1 × 2 = 2 × 3 of 3, 1 × 2 + 2 × 3 = 2 × 3 × 4 of 3, 1 × 2 + 2 × 3 + 3 × 4 = 3 × 4 × 5 of 3 (1) 1 × 2 + 2 × 3 + 3 × 4 + 4 × 5 = 4 × 5 × () (2) 1 × 2 + 2 × 3 + 3 × 4 + 4 × 5 + 5 × 6 = () × () × () （3）1×2+2×3+3×4+… +N × (n + 1) = () × () × () (4) 1 × (1 × 2 + 2 × 3 + 3 × 4 +) + 199 × 200) = (this one needs to be written)
6. Observe each of the following formulas and fill in the blanks according to the rules you find 4*5=20,3*6=18 5*6=30,4*7=28 6*7=42,5*8=40 . If 1222 * 1223 = 1494506, then 1221 * 1224 = () Write the relationship
7. 2 + 4 = 2 × 3 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 2 + 4 + 6 = 3 × 42 + 4 + 6 + 8 = 4 × 5 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 2 + 4 + 6 + 8 + 10 + +100=______ ×______ ．
8. First observe the following formula, fill in the blanks and summarize the rules 3²-1²=8×1, 5²-3²=8×2； Then (1) 7 & sup2; - 5 & sup2; = 8 × (3) （2）9²-(7)²=8×4 （3）(11)²-9²=8×5 Sum up the law____________________________________ .
9. Observe the following formula and fill in the blanks 1.07÷9＝0.118 1111.04÷9＝﹙ ﹚ 11.06÷91.228 ﹙ ﹚÷9＝﹙ ﹚ 111.05÷9＝12.338 ﹙ ﹚÷9=﹙ ﹚
10. Looking at the following formulas, what rules do you find? ①16×14=224=1×（1+1）×100+6×4 ②23×27=621=2×（2+1）×100+3×7 ③32×38=1216=3×（3+1）×100+2×8 Simple description of the above found rules: mainly text and letters
11. A column of numbers 0, negative 2,6, negative 12,20, negative 30,42, etc. write the eighth number and the nth number according to this rule Ask for answers
12. Observe the following regular numbers: 1 / 2, 1 / 6, 1 / 12, 1 / 20, 1 / 30, 1 / 42... What is the seventh? 1 / 380? What is the nth?
13. Observe the following regular numbers: 1 / 2, 1 / 6, 1 / 12, 1 / 20, 1 / 30, 1 / 42... Write the seventh and N numbers according to the law
14. Observe the following list of regular numbers: 1 / 2, 1 / 6, 1 / 12, 1 / 30, 1 / 42 (2) 1 / 272 is the number one in the column_ individual (3) Calculate the sum of the first 20 numbers
15. 1/2,1/6,1/12,1/30,1/42…… Find the rule, the nth number is () 1 / 132 is the number
16. 1 / 2, 1 / 6, 1 / 12, 1 / 20, 1 / 30, 1 / 42. According to the law, the seventh number is. The nth number is. 1 / 132 is the number
17. Formula calculation: 42 is 1 / 6 more than bracket
18. The law calculation of 1 / 12 + 1 / 20 + 1 / 30 + 1 / 42 + 1 / 56
19. Simple calculation 90.909-9.09 + 90.9
20. Ask a math question, the question is like this. 90.2 △ 75.1, find the quotient to you and check! Find the formula! I think it's our usual algorithm, which is used to eliminate the decimal point of the number! It's 75.1 △ 90.2