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A048448 a(n) = prime(n-1) + prime(n+1) (assuming prime(i) = 0 for i < 1). 28

%I #31 Sep 08 2022 08:44:57

%S 2,3,7,10,16,20,28,32,40,48,54,66,72,80,88,96,106,114,126,132,140,150,

%T 156,168,180,190,200,208,212,220,236,244,264,270,286,290,306,314,324,

%U 336,346,354,370,374,388,392,408,422,438,452,460,468,474,490,498,514

%N a(n) = prime(n-1) + prime(n+1) (assuming prime(i) = 0 for i < 1).

%C Starting from prime sequence add previous and next term yielding generation 2.

%C a(n) = A116366(n,n-2) for n>2. - _Reinhard Zumkeller_, Feb 06 2006

%C Arithmetic derivative (see A003415) of prime(n-1)*prime(n+1) for n > 1. - _Giorgio Balzarotti_, May 26 2011

%H G. C. Greubel, <a href="/A048448/b048448.txt">Table of n, a(n) for n = 0..10000</a>

%t Table[If[n < 2, Prime[n+1], Prime[n+1] + Prime[n-1]], {n, 0, 60}]

%t Join[{2,3},First[#]+Last[#]&/@Partition[Prime[Range[60]],3,1]] (* _Harvey P. Dale_, Jan 25 2016 *)

%o (PARI) je=[2,3]; for(n=1,60,je=concat(je, prime(n)+prime(n+2))); je \\ modified by _G. C. Greubel_, May 18 2019

%o (MuPAD) ithprime(i)+ithprime(i+2) $ i = 1..54 // _Zerinvary Lajos_, Feb 26 2007

%o (Magma) [2,3] cat [NthPrime(n-1) + NthPrime(n+1): n in [2..60]]; // _G. C. Greubel_, May 18 2019

%o (Sage) [2,3] + [nth_prime(n-1) + nth_prime(n+1) for n in (2..60)] # _G. C. Greubel_, May 18 2019

%o (GAP) Concatenation([2,3], List([2..60], n-> Primes[n-1] + Primes[n+1])) # _G. C. Greubel_, May 18 2019

%Y Generation 1 is the 'prime sequence A000040'. See A048449-A048466. See also A047844.

%K nonn

%O 0,1

%A _Patrick De Geest_, May 15 1999

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Last modified August 21 03:35 EDT 2024. Contains 375342 sequences. (Running on oeis4.)