

A097568


Least k such that k*P(n)#/2  4 and k*P(n)#/2 + 4 are consecutive primes with a gap of 8, where P(n)=nth prime, P(n)#=nth primorial.


0



93, 31, 27, 15, 9, 85, 5, 19, 47, 107, 35, 9, 109, 7, 55, 595, 63, 61, 133, 5, 21, 79, 109, 163, 561, 233, 99, 311, 165, 295, 731, 27, 459, 471, 705, 1057, 1459, 433, 11, 735, 413, 899, 163, 1085, 581, 13, 23, 945, 69, 3595, 743, 131, 945, 241, 223, 231, 509, 965
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OFFSET

1,1


LINKS

Table of n, a(n) for n=1..58.


EXAMPLE

27*2*3*5/2=405; 401 and 409 are consecutive primes with a gap of 8, for n=3, k=27


MATHEMATICA

nn=60; Module[{prmrls=(Rest[FoldList[Times, 1, Prime[Range[nn]]]])/2, k, c}, Table[ k=1; c=k*prmrls[[n]]; While[NextPrime[c]c!=4cNextPrime[c, 1]!=4, k++; c= k*prmrls[[n]]]; k, {n, nn}]] (* Harvey P. Dale, Mar 26 2013 *)


CROSSREFS

Sequence in context: A191948 A278860 A283897 * A086001 A106658 A033413
Adjacent sequences: A097565 A097566 A097567 * A097569 A097570 A097571


KEYWORD

nonn


AUTHOR

Pierre CAMI, Aug 28 2004


STATUS

approved



