7 、12、17、22、27、…… The 100th is____ The nth is______ 7 、12、17、22、27、…… The 100th is____ The nth is______

7 、12、17、22、27、…… The 100th is____ The nth is______ 7 、12、17、22、27、…… The 100th is____ The nth is______

100th: 502
The nth: 5N + 2

Find the sequence 121212121212 The general term formula of

1212 = 1200 + 12 = 12 (1 + 100) 12121212 = 12 (1 + 100 + 10000 + 1000000) = 12 (1 + 102 + 104 + 106), then the nth term of the sequence is an = 12 (1 + 102 + 104 +...) +102n-2）=12×102n−1100−1=433(102n−1)．

Formula of 12, 1212, 121212, 12121212
Find the leading formula of 1212121212, correct,

An=12(1+10^2+10^4-----+10^(2n-2))

Sequence 1 12 121 21 121 212. General term formula

The recurrence formula is a (n + 1) = an * 100 + 12, A1 = 1 [a (n + 1) + 4 / 33] = 100 (an + 4 / 33) an + 4 / 33 = 400 / 33 * 100 ^ (n-1) = 4 / 33 * 100 ^ (n-1) an = 4 / 33 * [100 ^ (n-1) - 1] and click "can solve + original"!