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a(n) = a(n-1) + prime(n-1), with a(1)=2.
5

%I #19 Sep 21 2016 18:17:06

%S 2,4,7,12,19,30,43,60,79,102,131,162,199,240,283,330,383,442,503,570,

%T 641,714,793,876,965,1062,1163,1266,1373,1482,1595,1722,1853,1990,

%U 2129,2278,2429,2586,2749,2916,3089,3268,3449,3640,3833,4030,4229,4440,4663

%N a(n) = a(n-1) + prime(n-1), with a(1)=2.

%C Old name was "a(n) = 2 + the sum of the first n-1 prime numbers".

%H Harvey P. Dale, <a href="/A036439/b036439.txt">Table of n, a(n) for n = 1..1000</a>

%t nxt[{n_,a_}]:={n+1,a+Prime[n]}; NestList[nxt,{1,2},50][[All,2]] (* _Harvey P. Dale_, Sep 21 2016 *)

%o (PARI) a(n) = 2 + sum(i=1, n-1, prime(i)); \\ _Michel Marcus_, Aug 12 2013

%Y A014284(n) + 1.

%K nonn,easy

%O 1,1

%A Pavel Bubak (pbub6070(AT)beta.ms.mff.cuni.cz)

%E More terms from _James A. Sellers_, Feb 06 2000

%E Offset changed and definition improved from _Bruno Berselli_, Jul 30 2013