login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A052213 Numbers n with prime signature(n) = prime signature(n+1). 7
2, 14, 21, 33, 34, 38, 44, 57, 75, 85, 86, 93, 94, 98, 116, 118, 122, 133, 135, 141, 142, 145, 147, 158, 171, 177, 201, 202, 205, 213, 214, 217, 218, 230, 244, 253, 285, 296, 298, 301, 302, 326, 332, 334, 375, 381, 387, 393, 394, 429, 434, 445, 446, 453, 481 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

pri[ n_ ] := Sort[ Transpose[ FactorInteger[ n ] ][ [ 2 ] ] ] Select[ Range[ 2,1000 ],pri[ # ]==pri[ #+1 ]& ]

LINKS

T. D. Noe, Table of n, a(n) for n=1..10000

MathOverflow, Question on consecutive integers with similar prime factorizations

EXAMPLE

14 = 2^1 7^1 and 15 = 3^1 5^1, so both have prime signature {1,1}.

CROSSREFS

Sequence in context: A138047 A005237 A140578 * A086263 A073143 A066613

Adjacent sequences:  A052210 A052211 A052212 * A052214 A052215 A052216

KEYWORD

easy,nonn

AUTHOR

Erich Friedman, Jan 29 2000

STATUS

approved

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

Content is available under The OEIS End-User License Agreement .

Last modified October 25 09:31 EDT 2014. Contains 248518 sequences.