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A089635 Smallest member of a pair of consecutive twin prime pairs that have three primes between them. 2
107, 239, 311, 569, 1229, 1427, 1997, 2687, 4049, 4127, 4157, 4481, 5231, 6089, 7559, 9629, 10457, 13829, 13901, 14249, 16187, 16649, 17207, 17597, 17957, 18059, 19841, 20507, 21317, 21491, 21557, 22481, 27689, 28109, 28277, 28349, 31769, 32141 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 3..1000

MATHEMATICA

Transpose[Select[Partition[Prime[Range[6, 4000]], 7, 1], #[[2]]-#[[1]]== #[[7]]- #[[6]] ==2&&#[[4]]-#[[3]]!=2&&#[[5]]-#[[4]]!=2&]][[1]](* Harvey P. Dale, Oct 07 2014 *)

PROG

(PARI) pbetweentw(n, p) = \p is the number of primes between { forstep(x1=1, n, 1, c=0; t1 = twin[x1]; t2 = twin[x1+1]; for(y=t1+4, t2-1, if(isprime(y), c++) ); if(c==p, print1(t1", ")) ) } savetwins(n) = \ build a twin prime table of lower bounds { twin = vector(n); c=1; forprime(x=3, n*10, if(isprime(x+2), twin[c]=x; c++; ) )

CROSSREFS

Cf. A105413.

Sequence in context: A141996 A142844 A142914 * A248402 A201220 A088563

Adjacent sequences:  A089632 A089633 A089634 * A089636 A089637 A089638

KEYWORD

easy,nonn

AUTHOR

Cino Hilliard, Jan 01 2004

EXTENSIONS

Cross-reference added by Harvey P. Dale, Oct 08 2014

STATUS

approved

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Last modified July 24 21:47 EDT 2021. Contains 346273 sequences. (Running on oeis4.)