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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A066749 List of primes p which are equal to a central binomial coefficient C(n,floor(n/2)) plus 1. 1
2, 3, 7, 11, 71, 127, 463, 3433, 2704157, 20058301, 17672631901, 35345263801, 2104098963721, 16123801841551, 6892620648693261354601, 51913710643776705684835561, 410795449442059149332177041 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

The corresponding values of n are in A067366.

EXAMPLE

For n=5 the central binomial coefficient is C(5,2)=10. Since 10+1=11 is prime, it is in the sequence.

MATHEMATICA

For[ n=0, True, n++, If[ PrimeQ[ z=Binomial[ n, Floor[ n/2 ] ]+1 ], Print[ z ] ] ]

PROG

(MuPAD) for n from 0 to 200 do p := binomial(n, floor(n/2))+1: if isprime(p) then print(p) end_if end_for

CROSSREFS

Cf. A001405, A067366.

Sequence in context: A175171 A073609 A053781 * A046480 A137767 A191704

Adjacent sequences:  A066746 A066747 A066748 * A066750 A066751 A066752

KEYWORD

nonn

AUTHOR

Frank Buss (fb(AT)frank-buss.de), Jan 16 2002

EXTENSIONS

Repetitions removed by N. J. A. Sloane (njas(AT)research.att.com), Apr 09 2008

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

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

Last modified February 16 05:39 EST 2012. Contains 205860 sequences.