|
| |
|
|
A094709
|
|
Smallest k such that prime(n)# - k and prime(n)# + k are primes, where prime(n)# = A002110(n).
|
|
3
|
|
|
|
0, 1, 1, 13, 1, 17, 59, 23, 79, 101, 83, 239, 71, 149, 367, 73, 911, 313, 373, 523, 313, 331, 197, 101, 1493, 523, 293, 577, 2699, 1481, 1453, 5647, 647, 419, 757, 4253, 509, 239, 10499, 191, 4013, 2659, 617, 6733, 1297, 971
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,4
|
|
|
COMMENTS
|
a(n) = A002110(n) - A094710(n) = A094711(n) - A002110(n),
Goldbach's conjecture implies that a(n) is defined for all n. - David Wasserman, May 31 2007
|
|
|
LINKS
|
David Wasserman, Table of n, a(n) for n = 1..250
|
|
|
EXAMPLE
|
a(4)=13 because prime(4)=7, 7# = 2*3*5*7 = 210, and 210 - 13 and 210 + 13 are primes.
|
|
|
MATHEMATICA
|
pc[n_]:=Module[{x=0, i=0}, Do[If[PrimeQ[n-i]&&PrimeQ[n+i], x=i; Break[]], {i, 9!}]; x]; r=2; lst={}; Do[p=Prime[n]; r*=p; AppendTo[lst, pc[r]], {n, 2, 2*4!}]; lst (* Vladimir Joseph Stephan Orlovsky, Jun 14 2009 *)
|
|
|
CROSSREFS
|
Cf. A078611.
Sequence in context: A010236 A058018 A037283 * A236231 A040181 A123187
Adjacent sequences: A094706 A094707 A094708 * A094710 A094711 A094712
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
Reinhard Zumkeller, May 21 2004
|
|
|
EXTENSIONS
|
More terms from Don Reble (djr(AT)nk.ca), May 27 2004
|
|
|
STATUS
|
approved
|
| |
|
|
