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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A097527 Least k such that k*P(n)#-P(n+3) and k*P(n)#+P(n+3) are both primes with P(i)=i-th prime and P(i)#=i-th primorial. 0
5, 3, 1, 1, 3, 2, 12, 2, 2, 29, 69, 33, 15, 9, 28, 8, 111, 121, 55, 92, 4, 269, 89, 138, 57, 102, 39, 113, 81, 79, 155, 85, 647, 482, 369, 29, 295, 81, 88, 1, 14, 229, 33, 350, 29, 85, 738, 143, 304, 217, 805, 2421, 166, 370, 616, 111, 621, 543, 160, 200, 1825, 909, 256 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

EXAMPLE

2*3*5-13=17 prime 2*3*5+13=43 prime so for n=3 k=1

MATHEMATICA

Primorial[n_] := Product[ Prime[i], {i, n}]; f[n_] := Block[{k = 1, p = Primorial[n], q = Prime[n + 3]}, While[k*p - q < 2 || !PrimeQ[k*p - q] || !PrimeQ[k*p + q], k++ ]; k]; Table[ f[n], {n, 63}] (from Robert G. Wilson v Aug 31 2004)

CROSSREFS

Sequence in context: A159671 A094853 A096937 * A132400 A063268 A179613

Adjacent sequences:  A097524 A097525 A097526 * A097528 A097529 A097530

KEYWORD

easy,nonn

AUTHOR

Pierre CAMI (pierre-cami(AT)bbox.fr), Aug 27 2004

EXTENSIONS

More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Aug 31 2004

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 17:46 EST 2012. Contains 205939 sequences.