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A052012 Number of primes between successive Lucas numbers. 4

%I

%S 1,0,1,0,2,2,4,6,9,15,20,31,48,72,110,170,257,400,608,950,1448,2256,

%T 3487,5413,8440,13118,20478,31932,49995,78222,122553,192262,301826,

%U 474039,745772,1173270,1848000,2912623,4593723,7249438,11448047

%N Number of primes between successive Lucas numbers.

%e Between Luc(7)=29 and Luc(8)=47 we find the following primes: 31, 37, 41 and 43 hence a(7)=4.

%t PrimePi[Last[#]-1]-PrimePi[First[#]]&/@Partition[LucasL[ Range[45]],2,1] (* _Harvey P. Dale_, Jun 28 2011 *)

%o (Haskell)

%o a052012 n = a052012_list !! (n-1)

%o a052012_list = c 1 0 $ tail a000204_list where

%o c x y ls'@(l:ls) | x < l = c (x+1) (y + a010051 x) ls'

%o | otherwise = y : c (x+1) 0 ls

%o -- _Reinhard Zumkeller_, Dec 18 2011

%Y Cf. A000204, A052011.

%Y Cf. A010051.

%K nonn,nice

%O 1,5

%A _Patrick De Geest_, Nov 15 1999

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Last modified June 20 13:53 EDT 2021. Contains 345165 sequences. (Running on oeis4.)