login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A145604 Number of pairs of consecutive integers x, x+1 such that both are prime(n)-smooth but both are not prime(n-1)-smooth. 11
1, 3, 6, 13, 17, 28, 40, 59, 74, 104, 137, 171, 216, 284, 349, 428 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

See A145605 for a triangle of x value. See A145606 for the largest x for each n.

LINKS

Table of n, a(n) for n=1..16.

FORMULA

First differences of A002071.

CROSSREFS

Sequence in context: A248043 A189420 A215972 * A053569 A310123 A293794

Adjacent sequences:  A145601 A145602 A145603 * A145605 A145606 A145607

KEYWORD

nonn,hard,more

AUTHOR

T. D. Noe, Oct 14 2008

EXTENSIONS

a(16) from Jean-Fran├žois Alcover, Nov 11 2016

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 6 11:51 EDT 2020. Contains 333273 sequences. (Running on oeis4.)