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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: A058018 A037283 A278634 * 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

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Last modified December 10 15:13 EST 2016. Contains 279003 sequences.