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A087904
a(n) = the number of twin primes j*(p(n)#)+-1, for 1<=j<(p(n+1))^2.
0
3, 10, 16, 19, 30, 40, 34, 45, 49, 47, 55, 53, 52, 53, 63, 74, 75, 68, 77, 73, 72, 73, 79, 95, 77, 67, 72, 84, 75, 94, 92, 96, 97, 100, 100, 94, 93, 107, 91, 92, 78
OFFSET
0,1
COMMENTS
p(n) is the n-th prime; # denotes primorial (A002110).
FORMULA
a(n) seems to grow like 16 log p(n).
EXAMPLE
a(2)=10 because for j in {1,2,3,5,7,10,12,17,18,23}, j*(3#)+-1 are primes.
CROSSREFS
Cf. A002110.
Sequence in context: A051420 A367257 A092827 * A242203 A093516 A246302
KEYWORD
nonn
AUTHOR
Pierre CAMI, Oct 14 2003
EXTENSIONS
Edited by Don Reble, Nov 16 2005
STATUS
approved