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Sum of first n terms equals n-th prime.
15

%I #27 Oct 25 2023 09:28:41

%S 2,1,2,2,4,2,4,2,4,6,2,6,4,2,4,6,6,2,6,4,2,6,4,6,8,4,2,4,2,4,14,4,6,2,

%T 10,2,6,6,4,6,6,2,10,2,4,2,12,12,4,2,4,6,2,10,6,6,6,2,6,4,2,10,14,4,2,

%U 4,14,6,10,2,4,6,8,6,6,4,6,8,4,8,10,2,10,2,6,4,6,8,4,2,4,12,8,4,8,4,6

%N Sum of first n terms equals n-th prime.

%C Except for first term, same as A001223.

%C First differences of A182986. - _Omar E. Pol_, Oct 31 2013

%C A075526 is 1 together with A001223. This is 2 together with A001223. A125266 is 3 together with A001223. - _Omar E. Pol_, Nov 01 2013

%C Convolved with A024916 gives A086718. - _Omar E. Pol_, Dec 23 2021

%t Join[{2},Differences[Prime[Range[100]]]] (* _Paolo Xausa_, Oct 25 2023 *)

%o (PARI) a(n) = if (n==1, 2, prime(n) - prime(n-1)); \\ _Michel Marcus_, Oct 31 2013

%Y Partial sums give A000040.

%Y Cf. A001223, A075526, A086718, A024916, A125266, A182986.

%K nonn

%O 1,1

%A _G. L. Honaker, Jr._, Apr 09 2000

%E More terms from _James A. Sellers_, Apr 11 2000