perplexus.info :: Sequences : Check this sequence

Check this sequence (Posted on 2020-08-24)

6,10,14,15,21,22,....ad inf

This sequence consists of products of two distinct primes.

1. What is the 1st appearance of 3 successive numbers?
2. How many triplets like n, n+1, n+2 are there below 2000?
3. Prove that 4 numbers in a succession cannot appear in this sequence.

No Solution Yet Submitted by Ady TZIDON

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Subject Author Date

parts 1 & 2 - computer solution Charlie 2020-08-24 20:07:33

Part 3 proof (spoiler) Steve Herman 2020-08-24 10:04:57

Part 3 proof (spoiler) Steve Herman 2020-08-24 10:04:55

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