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A185934 Lesser of two consecutive primes which both equal 1 (mod 3). 8
31, 61, 73, 151, 157, 199, 211, 271, 331, 367, 373, 433, 523, 541, 571, 601, 607, 619, 661, 727, 733, 751, 991, 997, 1033, 1063, 1069, 1117, 1123, 1201, 1231, 1237, 1291, 1321, 1381, 1453, 1459, 1531, 1543, 1621, 1657, 1669, 1741, 1747, 1753, 1759, 1777, 1789, 1861, 1987, 2011, 2131, 2161, 2179, 2281, 2287, 2341, 2371 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Or, primes of the form 6k+1 such that the next prime is again of the form 6k'+1.

a(n) = A217659(n) - 6*A219244(n); A217659(n) = A151800(a(n)). - Reinhard Zumkeller, Nov 16 2012

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

EXAMPLE

The smallest prime of the form 6k+1 such that the next larger prime differs by a multiple of 3 (and thus a multiple of 6), is a(1)=31, the following prime being 31+6=37.

Note that the next larger prime may also differ by 12 (as is the case for 199,211,619,661,997,1201,1237,1459,1531,1789,3049,...), or by 18 (as it is the case for 523,1069,1381,1759,2161,2503,3889,...), etc.

PROG

(PARI) forprime( p=1, 1e4, (o+0-o=p)%3==0 & o%3==1 & print1( precprime(p-1)", "))

(Haskell)

a185934 n = a185934_list !! (n-1)

a185934_list = map (a000040 . (+ 1)) $

   elemIndices 1 $ zipWith (*) a039701_list $ tail a039701_list

-- Reinhard Zumkeller, Nov 16 2012

CROSSREFS

Sequence in context: A228541 A115833 A189556 * A052158 A095672 A073650

Adjacent sequences:  A185931 A185932 A185933 * A185935 A185936 A185937

KEYWORD

nonn

AUTHOR

M. F. Hasler, Feb 06 2011

STATUS

approved

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Last modified November 18 13:22 EST 2018. Contains 317306 sequences. (Running on oeis4.)