A228611 Primes p such that the largest consecutive pair of p-smooth integers is the same as the largest consecutive pair of (p-1)-smooth integers.

23, 67, 83, 89, 97, 101

Offset

1,1

Comments

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

p = a(n) here equals prime(k) for 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, a(1) = 23 is a prime such that the largest consecutive pair of 23-smooth integers, (11859210,11859211), is the same as the largest consecutive pair of 22-smooth integers (or of 19-smooth integers, 19 being the next smaller prime).

Crossrefs

Cf. A002072, A117581, A228610 gives the index of the prime that is a(n) here.

Sequence in context: A001346 A051875 A125872 * A104945 A141849 A125873

Adjacent sequences: A228608 A228609 A228610 * A228612 A228613 A228614

Keyword

nonn,more,hard

Author

Don N. Page, Dec 18 2013

Status

approved