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A029854 gcd(prime(n)+prime(n+1), prime(n+1)+prime(n+2)). 1
1, 4, 6, 6, 6, 6, 6, 2, 4, 4, 2, 6, 6, 10, 4, 8, 8, 2, 6, 8, 2, 2, 2, 6, 6, 6, 6, 6, 6, 6, 2, 4, 12, 12, 4, 4, 10, 10, 4, 8, 12, 12, 6, 6, 2, 2, 2, 6, 6, 2, 8, 12, 4, 4, 4, 4, 4, 2, 6, 12, 24, 6, 6, 6, 18, 4, 4, 12, 6, 2, 2, 2, 4, 2, 2, 2, 6, 6, 18, 12, 12, 12, 8 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n) = gcd(A001043(n), A001043(n+1)).

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

EXAMPLE

a(20) = gcd(71+73, 73+79) = gcd(144,152) = 8*gcd(18,19) = 8.

MATHEMATICA

GCD[#[[1]]+#[[2]], #[[2]]+#[[3]]]&/@Partition[Prime[Range[90]], 3, 1] (* Harvey P. Dale, Mar 06 2014 *)

PROG

(PARI) a(n) = gcd(prime(n)+prime(n+1), prime(n+1)+prime(n+2)); \\ Michel Marcus, Aug 04 2013

(Haskell)

a029854 n = a029854_list !! (n-1)

a029854_list = zipWith gcd a001043_list $ tail a001043_list

-- Reinhard Zumkeller, Aug 08 2013

CROSSREFS

Sequence in context: A270541 A046262 A147862 * A329502 A141328 A298562

Adjacent sequences:  A029851 A029852 A029853 * A029855 A029856 A029857

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Feb 14, 2002

STATUS

approved

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Last modified January 19 21:47 EST 2020. Contains 331066 sequences. (Running on oeis4.)