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

1,1

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.

Links

Table of n, a(n) for n=1..6.

Example

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.

Sequence in context: A079368 A167529 A357184 * A106677 A350261 A091592

Adjacent sequences: A228607 A228608 A228609 * A228611 A228612 A228613

Keyword

nonn,more,hard

Author

Don N. Page, Dec 18 2013

Status

approved