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

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A047846 Number of successive odd nonprimes (A014076). 6
1, 1, 1, 1, 2, 2, 1, 1, 2, 2, 2, 1, 2, 1, 2, 3, 1, 1, 1, 6, 1, 2, 4, 2, 2, 1, 2, 2, 4, 1, 5, 5, 1, 1, 2, 4, 2, 2, 2, 2, 1, 4, 6, 1, 1, 6, 2, 4, 1, 2, 3, 2, 2, 1, 2, 3, 1, 3, 4, 4, 2, 1, 2, 3, 1, 1, 5, 3, 1, 3, 1, 2, 5, 8, 2, 4, 2, 2, 2, 4, 2, 2, 2, 2, 1, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

Beginning with a(2), length of n-th run of identical numbers in A160522 [Kyle Stern, Jun 19 2009]

a(n+1) = A196277(n+1) - A196277(n). [Reinhard Zumkeller, Sep 30 2011]

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

MATHEMATICA

Length /@ Split[Select[Range[1, 629, 2], PrimeOmega[#] != 1 &], #2 - #1 <= 2 &] (* Jayanta Basu, Aug 11 2013 *)

PROG

(Haskell)

a047846 n = a047846_list !! (n-1)

a047846_list = 1 : zipWith (-) (tail a196277_list) a196277_list

-- Reinhard Zumkeller, Sep 30 2011

CROSSREFS

Length of n-th run in A014076.

Cf. A160522.

Sequence in context: A102715 A254687 A182590 * A345699 A212632 A025885

Adjacent sequences:  A047843 A047844 A047845 * A047847 A047848 A047849

KEYWORD

easy,nonn

AUTHOR

Enoch Haga

EXTENSIONS

a(51) and a(84) corrected by Reinhard Zumkeller, Sep 30 2011

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 November 29 21:32 EST 2021. Contains 349416 sequences. (Running on oeis4.)