A228610 Numbers k such that the largest consecutive pair of prime(k)-smooth integers is the same as the largest consecutive pair of prime(k-1)-smooth integers.

9, 19, 23, 24, 25, 26

Offset: 1

Author

Don N. Page, Dec 18 2013

Keywords

• nonn
• more
• hard

Comments

For each such k = a(n), the smallest superparticular ratio R = m/(m-1) such that R factors into primes less than or equal to prime(k) have all of these prime factors strictly less than prime(k).

k = a(n) here are the values of k that make a(k) = a(k-1) in A002072 and also in A117581.

Examples

			For n = 1, k = a(1) = 9 gives prime(k) = 23 such that the largest consecutive pair of 23-smooth integers, (11859210,11859211), is the same as the largest consecutive pair of prime(k-1)-smooth integers (19-smooth integers).
		

Crossrefs

Cf. A002072, A117581, A228611 gives prime(k) corresponding to k here.