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

2, 3, 7, 10, 16, 20, 28, 32, 40, 48, 54, 66, 72, 80, 88, 96, 106, 114, 126, 132, 140, 150, 156, 168, 180, 190, 200, 208, 212, 220, 236, 244, 264, 270, 286, 290, 306, 314, 324, 336, 346, 354, 370, 374, 388, 392, 408, 422, 438, 452, 460, 468, 474, 490, 498, 514

Offset: 0

Author

Patrick De Geest, May 15 1999

Keywords

• nonn

Comments

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

a(n) = A116366(n,n-2) for n>2. - Reinhard Zumkeller, Feb 06 2006

Arithmetic derivative (see A003415) of prime(n-1)*prime(n+1) for n > 1. - Giorgio Balzarotti, May 26 2011

Links

• G. C. Greubel, Table of n, a(n) for n = 0..10000

Crossrefs

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

Programs

GAP

Concatenation([2,3], List([2..60], n-> Primes[n-1] + Primes[n+1])); # G. C. Greubel, May 18 2019

Magma

[2,3] cat [NthPrime(n-1) + NthPrime(n+1): n in [2..60]];  // G. C. Greubel, May 18 2019

Mathematica

Table[If[n < 2, Prime[n+1], Prime[n+1] + Prime[n-1]], {n, 0, 60}]
Join[{2,3},First[#]+Last[#]&/@Partition[Prime[Range[60]],3,1]] (* Harvey P. Dale, Jan 25 2016 *)

MuPAD

ithprime(i)+ithprime(i+2) $ i = 1..54 // Zerinvary Lajos, Feb 26 2007

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

Sage

[2,3] + [nth_prime(n-1) + nth_prime(n+1) for n in (2..60)] # G. C. Greubel, May 18 2019