Write the first four terms of each sequence whose general term is given. a_n = 7n - 4

Write the first four terms of each sequence whose general term is given. $a_n=1/(n-1)!$

Evaluate $\frac{40!}{4!38!}$

Find the indicated term of the arithmetic sequence with first term, , and common difference, d. Find a₁₂ when a₁ = -8, d = -2

Write a formula for the general term (the nth term) of each arithmetic sequence. Do not use a recursion formula. Then use the formula for a_n to find a₂₀, the 20th term of the sequence. -7, -3, 1, 5 ...

Find the sum of the first 22 terms of the arithmetic sequence: 5, 12, 19, 26, ...

Find 3 + 6 + 9 + ... + 300, the sum of the first 100 positive multiples of 3.

Use the formula for the sum of the first n terms of an arithmetic sequence to find the indicated sum.

${\sum }_{i=1}^{16}(3i+2)$

Write the first five terms of each geometric sequence. a₁ = 3, r = 2

Use the formula for the general term (the nth term) of a geometric sequence to find the indicated term of the sequence. Find a₇ when a₁ = 2, r = 3

Use the formula for the general term (the nth term) of a geometric sequence to find the indicated term of the sequence. Find a₅ when a₁ = -3, r = 2

Find the sum of the first 15 terms of the geometric sequence: 5, -15, 45, -135

Use the formula for the sum of the first n terms of a geometric sequence to find the indicated sum.

${\sum }_{i=1}^6{5}^i$

Find the sum of each infinite geometric series. 2 - 1 + 1/2 - 1/4 + ...