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 A145691 a(n)= least x such that 3*2^n*(3*2^n-x)-1 and 3*2^n*(3*2^n-x)+1 are twin primes 1
 1, 3, 6, 4, 18, 13, 24, 38, 11, 81, 14, 17, 66, 41, 41, 107, 59, 101, 34, 532, 209, 81, 119, 178, 53, 188, 244, 242, 66, 242, 157, 32, 16, 857, 21, 67, 233, 417, 727, 234, 189, 1381, 1854, 437, 129, 57, 749, 93, 531, 717, 21, 293, 311, 478, 874, 409, 686, 1667, 677, 52 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS As n increases sum a(n) from i=1 to n tends to (2*log(2)/3)^2*n*(n+1)*(2*n+1)/6 all verified values and certified primes in b145691 file LINKS Pierre CAMI, Table of n, a(n) for n = 1..600 EXAMPLE 3*2*(3*2-1)-1=29 prime as 31 so a(1)=1 CROSSREFS Sequence in context: A067979 A091808 A128719 * A009782 A016615 A224746 Adjacent sequences:  A145688 A145689 A145690 * A145692 A145693 A145694 KEYWORD nonn AUTHOR Pierre CAMI, Oct 16 2008 STATUS approved

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