Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A023193
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A023193 Conjecturally, a(n) is the largest number of primes that occurs on an infinite number of intervals of n consecutive integers. +0
5
1, 1, 2, 2, 2, 2, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 9, 9, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 13, 13, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19, 20, 20 (list; graph; listen)
OFFSET

1,3

COMMENT

According to the link at www.opertech.com, a(3159) >= 447 > 446 = pi(3159). The First Hardy-Littlewood conjecture (k-tuples conjecture) then implies that, for an infinitude of n, the interval [n+1, n+3159] includes 447 primes. For these n, pi(n+3159) >= pi(n)+447 > pi(n)+446 = pi(n)+pi(3159), contradicting the Second Hardy-Littlewood conjecture that pi(x+y) <= pi(x)+pi(y). - David W. Wilson (davidwwilson(AT)comcast.net), May 23 2005

LINKS

Eric Weisstein's World of Mathematics, Prime k-Tuples Conjecture.

Author?, Title?

T. Forbes, Prime k-tuplets.

FORMULA

Conjecturally, a(n) = lim sup pi(x+n)-pi(x), where pi = A000720. This would follow from the k-tuple conjecture. - David W. Wilson (davidwwilson(AT)comcast.net), May 23 2005

a(n) = minimum m such that A008407(m) >= n. [From Max Alekseyev (maxale(AT)gmail.com), Nov 03 2008]

CROSSREFS

Cf. A008407 (minimal difference of first and last prime in a prime k-tuplet), A047947 (Schinzel's rhobar), A066081 (weaker binary conjectures).

Least inverse is A020497.

Sequence in context: A024542 A098424 A098428 this_sequence A096605 A109497 A156078

Adjacent sequences: A023190 A023191 A023192 this_sequence A023194 A023195 A023196

KEYWORD

nonn

AUTHOR

David W. Wilson (davidwwilson(AT)comcast.net)

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified November 24 23:16 EST 2009. Contains 167481 sequences.


AT&T Labs Research