Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A096317
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A096317 a(n) is the minimal product of the smallest prime factor of each composite number in a prime gap of 2n. +0
2
2, 12, 120, 1680, 10080, 221760, 2217600, 34594560, 345945600, 11762150400, 29059430400, 988020633600, 21736453939200, 225268704460800, 5999261287219200, 642466345122201600, 1367831573485977600 (list; graph; listen)
OFFSET

1,1

EXAMPLE

a(5) = 10080: 2*5 = 10. The first occurrence of a prime gap of 10 comes after 139, with the composite numbers 140,141,142,143,144,145,146,147,148 whose smallest prime factors are 2,3,2,11,2,5,2,3,2, respectively. However, their product is 15840, which is not minimal. The 6th occurrence of a prime gap of 10 comes after 409, with the composite numbers 410,411,412,413,414,415,416,417,418 having the smallest prime factors 2,3,2,7,2,5,2,3,2 respectively. Their product is 10080, which is minimal.

CROSSREFS

Cf. A096318.

Sequence in context: A052580 A134095 A052680 this_sequence A081470 A108135 A001813

Adjacent sequences: A096314 A096315 A096316 this_sequence A096318 A096319 A096320

KEYWORD

nonn

AUTHOR

Ray G. Opao (1260(AT)email.com), Aug 02 2004

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 25 20:09 EST 2009. Contains 167514 sequences.


AT&T Labs Research